# 欺诈预防规则

使用欺诈预防规则保护您的业务。

Fraud prevention rules allow you to take action whenever a payment matches certain criteria. Stripe Radar provides built-in rules to help detect and protect you against fraud risk on card, ACH, and SEPA Direct Debit payments.

Radar for Fraud Teams and [Radar for Platforms](https://docs.stripe.com/radar/radar-for-platforms.md) let you use the [Dashboard](https://dashboard.stripe.com/test/radar/rules) to create custom rules based on the business logic specific to your business. For example, you can:

- 对支持 3DS 验证及新客户进行的所有付款**要求 3DS 验证\**
- \**允许\**来自您的电话中心的 IP 地址的所有付款
- \**阻止\**来自您的国家或国家以外的银行卡的付款
- **Review** all payments greater than 1,000 USD that were made with a prepaid card
- **Review and automatically pause payouts** on accounts that have a high dispute rate (with Radar for Platforms)

> 欧盟企业可能受到[地理封锁条例](https://support.stripe.com/questions/eu-geo-blocking-regulation-changes)及其关于禁止封锁欧盟成员国客户付款规定的影响。

## 内置规则

The following rules are available by default, unless flagged as custom rules, which are only available if you use Radar for Fraud Teams or Radar for Platforms.

> #### Block fraud automatically
> 
> Alternatively, you can use Radar [risk controls](https://docs.stripe.com/radar/risk-settings.md) to block fraud automatically. The risk controls use [early fraud warnings](https://docs.stripe.com/radar/risk-settings.md#early-fraud-warning) to evaluate and block the highest risk payments.

### AI 风险检查

All Radar offerings provide a set of default rules based on the judgments of our AI models.

| Radar rule                          | 描述                                                                                                                                                      |
| ----------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `if :risk_level: = 'highest'` (已废弃) | 对于欺诈风险高的付款，该规则会予以阻止，不予处理。默认情况下，所有 Radar 用户都会启用此规则。                                                                                                      |
| `if :risk_level: = 'elevated'`      | The default behavior for Radar for Fraud Teams and Radar for Platforms is to place payments into review that we suspect have an elevated risk of fraud. |

Radar for Platforms has additional account-level AI models that are incorporated through two default rules:

`if :account_risk_level: = 'highest'`

`if :account_risk_level: = 'elevated'`

We calculate account-level risk using KYC information, transactions, geographic signals, and behavior patterns.

### 传统银行卡检查

即使 *CVC* (The card verification code (CVC) or card verification value (CVV) is a three- or four-digit number printed directly on a card used to verify the entered card number) 或地址 (*AVS* (The address verification system (AVS) is used to pass billing address information to issuers to verify the data if available)) 检查失败，付款仍然可以成功，因为发卡行在决定授权付款时会评估大量信号。发卡行可能仍会认为未通过 CVC 或邮政编码验证的付款是合法的，因此会批准该付款。

您可以启用 Radar 的内置规则来阻止发卡行批准的某些付款。启用后，如果同时创建卡和客户，这些规则还会影响向客户关联卡和创建客户。

#### CVC 和 AVS 规则

自 2024 年 12 月 17 日起，管理平台将向未使用旧版 CVC 或 AVS 规则的新客户和现有客户显示这些规则。

| Radar rule          | 描述                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| ------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| CVC 验证失败时（基于风险）```` | Enable this rule to block payments that fail a card issuer’s CVC verification check, unless Stripe evaluates it as low risk. This rule doesn’t block payments where the customer doesn’t provide the CVC number because they, for example, use a *wallet* (A digital wallet is a contactless payment method that stores payment options, such as credit and debit cards, allowing customers to use a smart device to make a purchase), or their card issuer doesn’t support its verification. |
| 邮编验证失败时（基于风险评分）```` | Enable this rule to block payments that fail a card issuer’s postal code verification check, unless Stripe evaluates it as low risk. This rule doesn’t block payments where the customer doesn’t provide the postal code, or their card issuer doesn’t support its verification.                                                                                                                                                                                                              |

#### 旧版 CVC 和 AVS 规则

Effective December 17, 2024, the Dashboard shows these rules to existing customers who enabled at least one of the rules.

| Radar rule                          | 描述                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| ----------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `if CVC verification fails`         | Enable this rule to block payments that fail a card issuer’s CVC verification check. This rule doesn’t block payments where the customer doesn’t provide the CVC number because they, for example, use a *wallet* (A digital wallet is a contactless payment method that stores payment options, such as credit and debit cards, allowing customers to use a smart device to make a purchase), or their card issuer doesn’t support its verification. |
| `if postal code verification fails` | Enable this rule to block payments payments when they fail a card issuer’s postal code verification check. This rule doesn’t block payments where the customer doesn’t provide the postal code, or their card issuer doesn’t support its verification.                                                                                                                                                                                                |

### 内置请求 3DS 验证的规则

*3D Secure (3DS)* (3D Secure (3DS) provides an additional layer of authentication for credit card transactions that protects businesses from liability for fraudulent card payments) prompts customers to complete an additional authentication step before they can complete the purchase flow. If 3DS authenticates a payment, the [liability](https://docs.stripe.com/payments/3d-secure/authentication-flow.md#disputed-payments) for any fraud-related disputes for that payment typically shifts from the seller to the issuer. This means that in most cases, the seller isn’t responsible for fraud costs on 3DS authenticated payments.

Stripe automatically handles soft decline codes indicating that 3DS is required by issuers. We also trigger 3DS when necessary, adhering to regulations, such as the [Strong Customer Authentication](https://stripe.com/guides/strong-customer-authentication) (SCA) mandated by the PSD2. Disabling Radar doesn’t prevent 3DS from being triggered in cases where it’s necessary.

Stripe supports three legacy built-in rules to request 3DS when using Radar with [Payment Intents](https://docs.stripe.com/payments/accept-a-payment.md) or [SetupIntents](https://docs.stripe.com/payments/save-and-reuse.md):

| Radar rule                          | 描述                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| ----------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `如果 卡片推荐使用 3DS 验证` (已弃用)            | Enable this rule to prompt the customer for 3DS authentication based on risk.                                                                                                                                                                                                                                                                                                                                                            |
| `如果 卡片支持 3DS 验证` (已弃用)              | Enable this rule to prompt the customer for 3DS authentication, as long as their card supports it.                                                                                                                                                                                                                                                                                                                                       |
| 如果要求对某卡进行 3DS 验证``(Deprecated)，则`。` | Enable this rule to prompt the customer for 3DS authentication, if the card historically [required 3DS](https://docs.stripe.com/payments/3d-secure/authentication-flow.md#three-ds-cards). Regardless of this rules, Stripe automatically triggers 3DS:
  - 如果软拒绝代码指示发卡行需要 3DS 验证。
  - In adherence to regulations, such as the PSD2 [Strong Customer Authentication](https://stripe.com/guides/strong-customer-authentication) mandate. |

由于 3DS 验证要求您的客户进行额外一层身份验证，因此不加选择地使用 3DS 验证可能会降低转化率。

Requesting 3DS doesn’t necessarily mean the issuer actually performs 3DS. Learn more about [possible outcomes](https://docs.stripe.com/payments/3d-secure.md).

### 自定义规则来请求 3DS 验证并对特定结果采取行动

尝试 3DS 验证后，如果您有 [Radar 风控团队版](https://stripe.com/radar/fraud-teams) 或 [Radar for Platforms](https://docs.stripe.com/radar/radar-for-platforms.md)，则可以在允许、阻止或查看规则中评估结果。

See below for the most important attributes for custom Radar rules.

| Attribute                    | 描述                                                                                                                                                                                                                                                                                                                                                                                              |
| ---------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `is_3d_secure`               | This is true if the card is supported, 3DS was attempted by the issuer, and the customer didn’t fail authentication. We generally recommend using this in block rules.                                                                                                                                                                                                                          |
| `is_3d_secure_authenticated` | This is true if 3DS was attempted by the issuer and the customer successfully completed a full authentication. Using this attribute in a block rule excludes legitimate transactions that might have an SCA exemption or don’t fall into a clear failure or successful authentication, such as processing errors.                                                                               |
| `has_liability_shift`        | This is true if Stripe expects *liability shift* (With some 3D Secure transactions, the liability for fraudulent chargebacks (stolen or counterfeit cards) shifts from you to the card issuer) to cover the payment. This might not always be the same as [3DS](https://docs.stripe.com/payments/3d-secure/authentication-flow.md#disputed-payments), for example Apple Pay in certain regions. |

For custom rules, we recommend keeping `Request 3DS` and `Block` rules aligned depending on your [risk appetite](https://stripe.com/guides/improve-fraud-management-with-radar-for-fraud-teams-and-stripe-data). However, don’t block payments where 3DS isn’t supported, such as from some wallets.

See below for some examples that show how to achieve this for different use cases.

#### 基于 Radar 风险等级要求 3DS 验证

You want to use Radar to request 3DS on all payments, based on the risk level and that are above a certain amount.

| Radar rule                                                               | 描述                                                                                                                                          |
| ------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------- |
| `Request 3D Secure if :risk_level: != 'normal' and :amount_in_usd: > 25` | This rule checks for the Radar risk level before requesting 3DS on all payments with an elevated or high risk level above a certain amount. |

In this case, without a block rule, cards or wallets that don’t support 3DS aren’t blocked. 3DS attempts that failed authentication don’t continue to charge authorization.

#### 始终基于 Radar 风险等级要求 3DS 验证

You want to use Radar to request 3DS on all payments, based on an elevated or high risk level and that are above a certain amount. You don’t want to support cards that don’t support 3DS.

| Radar rule                                                                                                                                                                                                               | 描述                                                                                                                                                                                                                                                                                                                                                                                                      |
| ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `Request 3D Secure if :risk_level: != 'normal' and :amount_in_usd: > 25`                                                                                                                                                 | This rule checks for the Radar risk level before requesting 3DS on all charges with an elevated or high risk level above a certain amount.                                                                                                                                                                                                                                                              |
| `Block if not :is_3d_secure:  and :risk_level: != 'normal' and :amount_in_usd: > 25 and  not :is_off_session:  and  :digital_wallet: != 'apple_pay'  and  not (:digital_wallet: = 'android_pay'  and  :has_cryptogram:)` | This rule blocks elevated or high-risk payments above a certain amount that don’t have a 3DS flow. This rule accepts legitimate payments that might have an SCA exemption or don’t have a clear failure or successful authentication, such as `attempt_acknowledged`. It accepts off-session payments, such as recurring subscription charges, and wallets, such as Apple Pay or Google Pay to succeed. |

#### Only accept fully 3D Secure authenticated payments if 3D Secure is supported

You rely on Stripe activating 3DS when necessary in cases such as [Strong Customer Authentication](https://stripe.com/guides/strong-customer-authentication) (SCA), but don’t want to accept [edge cases](https://docs.stripe.com/api/charges/object.md#charge_object-payment_method_details-card-three_d_secure-result), such as processing errors.

| Radar rule                                                     | 描述                                                                                                                                                                                                                                                                                                         |
| -------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `Block if :is_3d_secure: and not :is_3d_secure_authenticated:` | This rule blocks payments where the card is enrolled in 3DS, and 3DS was attempted but the user didn’t successfully authenticate. Cards that don’t support 3DS, SCA exemptions, off-session payments (such as recurring subscription charges), and wallets (such as Apple Pay or Google Pay) are accepted. |

#### Request 3D Secure based on metadata

You want to use Radar to request 3DS on all payments with a custom metadata attribute.

| Radar rule                             | 描述                                                                                                                                                                         |
| -------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `Request 3D Secure if ::foo:: = 'bar'` | This rule checks for a metadata condition and then requests 3DS. To check customer metadata, replace `::foo:: = 'bar'` with a value like `::customer:trusted:: = 'false'`. |

In this case, without a block rule, we don’t block cards or wallets that don’t support 3DS. 3DS attempts that failed authentication don’t continue to charge authorization.

#### Always require 3D Secure based on metadata

You want to use Radar to request 3DS on all payments with a custom metadata attribute and block cards that don’t support it.

| Radar rule                                                                                                                                                                   | 描述                                                                                                                                                                                                                                                                                                                                                                                                      |
| ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `Request 3D Secure if ::foo:: = 'bar'`                                                                                                                                       | This rule checks for a metadata condition and then requests 3DS. To check customer metadata, replace `::foo:: = 'bar'` with a value like `::customer:trusted:: = 'false'`.                                                                                                                                                                                                                              |
| `Block if ::foo:: = 'bar' and not :is_3d_secure and not :is_off_session: and :digital_wallet: != 'apple_pay' and not(:digital_wallet: = 'android_pay' and :has_cryptogram:)` | This rule blocks payments that don’t have a 3DS flow for charges with a custom metadata attribute. This rule accepts legitimate payments that might have an SCA exemption or don’t have a clear failure or successful authentication, such as `attempt_acknowledged`. It accepts off-session payments, such as recurring subscription charges, and wallets, such as Apple Pay or Google Pay to succeed. |

#### 对所有新卡要求 3DS 验证，并且在不支持 3DS 验证时进行审核

You want to use Radar to request 3DS on all new cards and manually review payments from cards that don’t support 3DS.

| Radar rule                                                                                                                                               | 描述                                                                                                                                                                                                                                                                                                                             |
| -------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `Request 3D Secure if is_missing(:seconds_since_card_first_seen:)`                                                                                       | This rule requests 3DS on all cards that haven’t been used on your account. To reduce user friction, you can add a condition to only request 3DS if `:risk_level: != 'normal'`.                                                                                                                                                |
| `Request 3D Secure if :is_new_card_on_customer:`                                                                                                         | As an alternative to the rule above, this rule requests 3DS on all cards that are newly used on a [Customer](https://docs.stripe.com/api/customers.md). To reduce user friction, you can add a condition to only request 3DS if `:risk_level: != 'normal'`.                                                                    |
| `Review if not :is_3d_secure and not:is_off_session: and :digital_wallet: != 'apple_pay' and not(:digital_wallet: = 'android_pay' and :has_cryptogram:)` | This rule marks payments where 3DS is expected, but isn’t supported for manual review. It ignores off-session payments, such as recurring subscription charges, and wallets, such as Apple Pay or Google Pay. Payments marked for review continue to authorization and can give additional signals, such as issuer CVC checks. |

In this case, without a block rule, we don’t block cards or wallets that don’t support 3DS. 3DS attempts that failed authentication don’t continue to charge authorization.

#### 对某些发卡行国家，始终要求 3DS 验证

You want to use Radar to request 3DS on all payments from card issuers originating from countries on a [custom list](https://docs.stripe.com/radar/lists.md) and block the cards that don’t support it.

| Radar rule                                                                                                                                                                                       | 描述                                                                                                                                                                                                                                                                                                                                                                                                              |
| ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `Request 3D Secure if :card_country: in @enforce_3ds_list`                                                                                                                                       | This rule checks for a condition based on the card issuer’s country of origin and compares them to a [custom list](https://docs.stripe.com/radar/lists.md). If they match, we request 3DS.                                                                                                                                                                                                                      |
| `Block if :card_country: in @enforce_3ds_list and not :is_3d_secure and not :is_off_session: and :digital_wallet: != 'apple_pay' and not(:digital_wallet: = 'android_pay' and :has_cryptogram:)` | This rule blocks payments that don’t have a 3DS flow and that originate from countries on the custom list. This rule accepts legitimate payments that might have an SCA exemption or don’t have a clear failure or successful authentication, such as `attempt_acknowledged`. It accepts off-session payments, such as recurring subscription charges, and wallets, such as Apple Pay or Google Pay to succeed. |

#### 始终基于 Radar 风险级别要求 3DS 验证，并审核极端情况

You want to use Radar to request 3DS on all payments based on the risk level, and block cards that don’t support 3DS, but manually review edge cases.

| Radar rule                                                                                                                                                                                                     | 描述                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `Request 3D Secure if :risk_level: != 'normal'`                                                                                                                                                                | This rule checks for the Radar risk level before requesting 3DS on all elevated or high-risk payments above a certain amount.                                                                                                                                                                                                                                                                                                                 |
| `Block if not :is_3d_secure:  and :risk_level: != 'normal' and  not :is_off_session:  and  :digital_wallet: != 'apple_pay'  and  not (:digital_wallet: = 'android_pay'  and  :has_cryptogram:)`                | This rule blocks elevated or high-risk payments above a certain amount and that don’t have a 3DS flow. This rule accepts legitimate payments that might have an SCA exemption. It accepts off-session payments, such as recurring subscription charges, and wallets, such as Apple Pay or Google Pay to succeed.                                                                                                                              |
| `Review if not :is_3d_secure_authenticated:  and :risk_level: != 'normal' and  not :is_off_session:  and  :digital_wallet: != 'apple_pay'  and  not (:digital_wallet: = 'android_pay'  and  :has_cryptogram:)` | This rule marks payments that used 3DS, but didn’t result in a fully authenticated flow, for manual review. This reviews [edge cases](https://docs.stripe.com/api/charges/object.md#charge_object-payment_method_details-card-three_d_secure-result), such as `attempt_acknowledged`, and also marks legitimate payments despite SCA exemptions. Because review rules are evaluated after block rules, we block cards that don’t support 3DS. |

## Create rules

仅账户所有者、管理员和开发人员可创建规则。如果您需要[团队成员](https://support.stripe.com/questions/can-i-invite-other-team-members-or-my-developer-to-use-my-stripe-account)来创建规则，请检查您的[团队设置](https://dashboard.stripe.com/settings/team)以确保他们具有管理员权限。

The Stripe default rules can block a substantial number of fraudulent payments. Businesses that need more control over which payments they want to review, allow, or block can write custom rules through Radar for Fraud Teams. Platforms can write custom rules through Radar for Platforms to calibrate payments risk for their platform and connected accounts and apply account-specific rules.

在决定是否启用自定义规则时，请考虑以下因素：

- If you see certain features or user behaviors as more risky (for example, using a disposable email).
- If you want to implement rules based on the payment method (for example, automatically blocking SEPA Direct Debit payments that exceed a certain risk score).
- If you want to implement rules based on payment amounts or perceived risk level (for example, automatically review if the payment is over 500 USD, automatically allow if the payment is under 5 USD).
- If your existing disputed and refunded payments share any common patterns (for example, similar amounts, card types, or countries).
- If you have existing rules you want to migrate to Stripe. The Stripe AI model might already cover many of these rules, and you can check how our system performs for your business before customizing it.
- If you want to automatically raise reviews and optionally pause payouts on accounts. This applies to platforms only.

### Create effective rules 

While rules can help you automate your existing workflows, they can also negatively affect your business if used incorrectly. For example, a rule can automatically allow a large number of elevated or high-risk payments or block a large number of legitimate payments, if it isn’t set up properly.

Remember the following when setting up rules:

- 默认情况下，规则适用于所有 Radar 支持的支付方式，除非您使用 `payment_method_type` 属性在规则谓词中定义特定的支付方式。
- Rules only apply to future payments and don’t apply to any that you already processed.
- 仅在使用 [Stripe Checkout](https://docs.stripe.com/payments/checkout.md)、[Payment Intents](https://docs.stripe.com/payments/accept-a-payment.md) 或 [Setup Intents](https://docs.stripe.com/payments/save-and-reuse.md) 时才要求 3DS 验证规则，并在应用审核、阻止和允许规则之前先对其进行评估。
- Before implementing any block rule to block all payments or pause payouts for accounts that meet its criteria, consider whether you’d rather review the payments or accounts first.
- Implement any allow rules minimally, because they override the Stripe default rules, along with any other custom rules that match the same criteria.
- 您最多可以创建 200 条交易规则和 100 条账户规则。

## 构建交易规则

You can add and manage rules from the [Radar Rules page](https://dashboard.stripe.com/test/radar/rules) in the Dashboard.

#### To add a transaction rule

1. 点击 **+ 添加规则**。
1. Select the rule type.
1. 在规则编辑器中，用语法 `{action} if {attribute} {operator} {value}` 构建一个规则，其中：
   - `{action}`: is how Radar responds when the rule criteria is met. This value is pre-populated based on the rule type you selected.
   - `{attribute}`: is the element of the payment to evaluate, such as the amount or card type. Begin typing with `:` to open a list of valid attributes. You can also evaluate your custom metadata by enclosing it in double colons, for example, `::product_sku::`.
   - `{operator}`: is how to compare the attribute to the value, such as `=`, `>`, `!=`, and so on.
   - `{value}`: is the value of the attribute to evaluate.
1. 点击**测试规则**。
1. 如有必要，修改检测到的验证错误。
1. On the **Review new rule** page, review how this rule performs against your recent payments to confirm whether you want to enable it. If the rule might impact payments from more than one payment method, use the filter to view rule performance by payment method (for example, ACH or Cards).
1. Click **Add rule** to apply this rule to all future transactions.

### 使用 Radar 助手：

The Stripe rule editor has a built-in LLM assistant that constructs a Radar transaction rule from a natural language prompt. Learn more about [Stripe AI services](https://support.stripe.com/questions/use-of-artificial-intelligence-\(ai\)-in-stripe-services).

> #### Training data consent
> 
> By using Radar Assistant you agree that Stripe can log and use your chat entries to train and improve the Radar Assistant capabilities. If you don’t want to have your chat entries used for this purpose, write rules manually.

#### To use Radar Assistant

1. On the [Radar Rules page](https://dashboard.stripe.com/test/radar/rules), click **+ Add rule**.
1. Select the rule type.
1. 在规则编辑器中，点击 **Radar 助手**。
1. In the message field, enter your rule request. You might ask to:
   - *审核银行卡和 IP 国家不同的付款。*
   - *阻止超过 1000 美元的 Discover 付款。*
   - *允许从 stripe.com 邮件地址付款。*
1. When the Assistant returns its suggestion, you can either enter an additional command to make adjustments to the rule, or you can click **Test rule** to see how the rule performs against your recent transaction history.
1. When you’re satisfied with the rule, click **Add rule** to enable it for all future transactions.

> #### 分享您的反馈
> 
> 帮助我们继续改进 Radar 助手。点击**分享反馈**，并告诉我们您的助手的表现情况以及我们需要改进的地方。无论是关于建议的准确性、用户界面还是交互的任何其他方面，我们欢迎所有意见。

### 审核规则

Stripe still processes payments normally when they match a review rule’s criteria. We add these payments to your [review queue](https://dashboard.stripe.com/test/radar) so your team can review them more closely. Setting up a rule that’s too broad can result in too many payments placed in your review queue, slowing down your customers and burdening your review team.

The Stripe rule testing interface runs a simulation on the last 6 months of charges to determine how many legitimate, fraudulent, and blocked payments would have been affected by the rule, had it been implemented. While testing a rule and examining the last 6 months, make sure that:

- **Overall volume of payments is low**. Reviewing these payments shouldn’t create a burden for your team.
- **Human reviewers add value**. A human reviewer can generally identify an elevated or high-risk payment with greater confidence than the automated system.
- **The rule results in a mix of successful and refunded or disputed payments**. This means that additional inspection on these types of payments can help separate legitimate payments from fraudulent payments.

下例中的公司希望审核预付信用卡付款，看看如何提升他们创建的审核规则。

| 原始规则                                                    | 改进的规则                                                                 |
| ------------------------------------------------------- | --------------------------------------------------------------------- |
| `if :card_funding: = 'prepaid'`                         | `if :is_disposable_email: and :card_funding: = 'prepaid'`             |
| This rule is too broad and results in too many reviews. | This rule is more focused and results in a smaller number of reviews. |

### 阻止规则

You can use block rules to block payments that you’re confident are fraudulent, or based on any restrictions your business has in place (such as blocking payments from prepaid cards). If you’re not sure how to apply block rules, we recommend using a review rule to place payments in review. After reviewing these payments for potential false positives, you can confirm whether you want to create a block rule instead.

阻止规则只影响欺诈性付款和成功的付款，因为已经被阻止的付款不会受到影响。测试规则时，需确保：

- **尽可能减少误报**。在测试过程中，Stripe 会识别与规则匹配的成功付款和有争议付款的数量。一个好的阻止规则会导致被阻止的欺诈性付款比合法付款多得多。
- **Minimize unnecessary rules**. If your rule appears to perform well but is already covered by an existing rule, your newer rule might not be necessary. Similarly, if the results during testing appear to be mixed, consider setting up a review rule instead so you can gather more information about those types of payments.

The following is an example of how to improve a block rule created by a business that has a high level fraud from payments outside the US.

| 原始规则                                                                    | 改进的规则                                                                 |
| ----------------------------------------------------------------------- | --------------------------------------------------------------------- |
| `if :card_country: != 'US'`                                             | `if :card_country: != 'US' and :risk_level: = 'elevated'`             |
| This rule is too broad and blocks a high number of legitimate payments. | This rule is more focused and results in a smaller number of reviews. |

### 允许规则

If you want the ability to create allow rules, [contact us](https://support.stripe.com/contact).

允许规则会覆盖您的所有其他规则，因此请谨慎使用。很多公司可能不需要实施允许规则。如果您担心允许规则会允许少量的欺诈性付款通过，可以考虑进行调整，以进一步限制这些规则，然后再实施这些规则。

创建规则后，允许规则会立即应用到所有新付款。其中包括与之前阻止的付款类似的任何付款。测试规则时，需确保：

- **Examine the number of previously blocked payments that would have been allowed**. Allow rules override all other rules and Stripe’s risk assessment. When testing a new allow rule, all payments shown would have been allowed if this rule were active. This can include payments that had been blocked or disputed, impacting your future dispute rates.
- **Continue to block any high-risk payments**. Block high-risk payments by adding the following to any allow rule: `and :risk_level: != 'highest'`
- **评估您的业务中合法交易的记录**。您可以分析您自己的客户之间的关联，根据合法交易的记录来允许较高金额的交易。这有助于减少阻止在您这里有良好交易记录的客户的付款。为此，可以查看[属性列表](https://docs.stripe.com/radar/rules/reference.md#supported-attributes)并查找包含关键词“customer”的属性。

The following is an example of how to improve an allow rule for a business that generally (but not always) sees legitimate payments coming from customers in the UK:

| 原始规则                                                        | 改进的规则                                                                                      |
| ----------------------------------------------------------- | ------------------------------------------------------------------------------------------ |
| `if :ip_country: = 'GB'`                                    | `if :ip_country: = 'GB' and :risk_level: != 'highest'`                                     |
| This rule is too broad and allows some fraudulent payments. | This rule is more focused and results in allowing a smaller number of fraudulent payments. |

## Maintain your rules

As your business continues to grow, make sure your rules continue to reflect the types of customers that you want to do business with. The following are some best practices to keep rules current for the state of your business.

### Regularly monitor rules to make sure they’re still effective 

#### 规则指标

欺诈模式是不断变化的，因为我们提供[指标](https://dashboard.stripe.com/settings/radar/rules)来显示这些规则的表现效果。这些指标依规则类型而不同，因为不同类型的规则执行不同的操作。
![](https://b.stripecdn.com/docs-statics-srv/assets/rule-performance.8d495f28c352641ff7b710df3c3df2ed.png)

You might notice a difference in the number of payments that matched review rules and the number of payments sent to your review queue in the same time period. Because only *successful* payments are placed in review, payments that match a review rule’s criteria but get declined by the issuer, for example, aren’t sent to your review queue.

Use the **rule performance chart** to understand the behavior of your Radar rules. Look for unexpected spikes or declines in the number of payments matching your rules, such as allow rules letting through too many payments or block rules blocking too many. These spikes might indicate a change in the types of payments your business receives or that might necessitate updates to the rules.

**Color-coded lines** track the number of payments that match [3DS](https://docs.stripe.com/issuing/3d-secure.md) rules, allow rules, block rules, and review rules. Updated rules are displayed as **triangular symbols** on the graph lines, and can help you compare the impact of a change before and after you make it.

Click the overflow menu (⋯) to view additional commands for any rule, including **Disable**, **Enable**, **Edit** or **Delete**.

You can also use our reporting products, Sigma and Data Pipelines, to [query disputes and fraud data](https://docs.stripe.com/stripe-data/query-disputes-and-fraud-data.md), including rule decisions and attributes for each individual payment.

#### 评估规则的有效性

You can find information about the effectiveness of your rules and see how many payments each rule has affected. You can also view and download a filtered list of every payment that a rule has been applied to.

Review the sample questions in the following table to help you decide if you need to make changes to any rules or remove them entirely.

| Rule type | 评估                                                                                             | 需考虑的动作                                                                                                                                                                                                          |
| --------- | ---------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| 一般        | If this rule no longer matches any payments.                                                   | 删除该规则。                                                                                                                                                                                                          |
|           | 如果该规则有异常行为，例如允许的付款多于之前时段。                                                                      | Manually review payments that match this rule to determine if this is the behavior you want.                                                                                                                    |
| 3DS       | If the 3DS completion rate is high, but the number of disputes or early fraud warnings is low. | Remove the rule because you might be causing friction for your users.                                                                                                                                           |
|           | 如果通过 3DS 验证的交易欺诈率高。                                                                            | Consider modifying your 3DS rule into a block rule to prevent these users from passing frictionless flow (controlled by issuers) or committing first-party fraud.                                               |
|           | 如果 3DS 验证转化率低。                                                                                 | This might be an effective rule because it might be mostly blocking fraudsters. Consider manually investigating matched payments to make sure your good users aren’t abandoning because of additional friction. |
| 允许        | If the number of disputes, early fraud warnings, refunds, or failed payments is high.          | 取消允许不良付款通过的规则。                                                                                                                                                                                                  |
| 阻止        | If the number of blocks is going down, but your fraud is still steady or increasing.           | 修改您的规则，因为它可能已不再有效。                                                                                                                                                                                              |
|           | 如果被阻止的数量上升，而您的欺诈率仍未改变甚至出现升高的情况。                                                                | Modify your rule because it might block good users.                                                                                                                                                             |
|           | If the number of blocks is going up, and your fraud is going down.                             | This might be an effective rule. Consider manually reviewing a few transactions to make sure you’re not blocking too many good users.                                                                           |
| 人工审核      | 如果接受审核的付款比例低。                                                                                  | Make the rule more restrictive because it might be too broad.                                                                                                                                                   |
|           | 如果成功的付款或被批准的付款的数量多。                                                                            | Remove the manual review rule entirely, or write an allow rule to target those payments.                                                                                                                        |
|           | If the number of refunds or disputes and early fraud warnings are high.                        | 转换为阻止规则。                                                                                                                                                                                                        |

#### Request 3DS rules

For request 3DS rules, we display **3DS Requested**, which is the number of times a rule triggered a 3DS request. You can click a 3DS rule to see the following metrics.
![](https://b.stripecdn.com/docs-statics-srv/assets/request-credentials-rule-details.c22b65bc432aafec9e5bcb6079c53528.png)

**允许规则**

If you use Radar for Fraud Teams, you can view the following allow rules:

- **Allowed payments**: The total number of payments allowed by your rules.
- **Volume, allowed payments**: The total amount, in your local currency, associated with payments allowed by your rules.
- **Risk score**: The corresponding [risk outcomes](https://docs.stripe.com/radar/risk-evaluation.md#risk-outcomes) assigned by our AI models to the set of payments allowed by your rules.
- **Disputes from overrides**: The total number of allowed payments that were disputed.
- **Volume, disputes from overrides**: The total amount, in your local currency, associated with disputes from allowed payments.

> If the disputed metrics are high, you might consider writing more narrowly targeted allow rules, to prevent allowing payments through that are eventually disputed.

Select an allow rule to see the following metrics:
![](https://b.stripecdn.com/docs-statics-srv/assets/allow-rule-details.e8da078613fdbca5592d2f9330c0f6d4.png)

**阻止规则**

You can view the following block rules:

- **Blocked payments**: The total number of payments blocked by your rules.
- **Volume, blocked payments**: The total amount, in your local currency, associated with payments blocked by your rules.

If you use Radar for Fraud Teams, you can also view the following:

- **Risk score**: The corresponding [risk outcomes](https://docs.stripe.com/radar/risk-evaluation.md#risk-outcomes) assigned by our AI models to the set of payments allowed by your rules.
- **Est. false positive rate**: The estimated percentage of non-fraudulent payments that were blocked for both your block rules as a set and by individual rules. These estimates are made using the estimated false positive rates of the corresponding AI risk scores, which we calculate with experiments across the Stripe network.
- **Est. fraudulent payments prevented**: The estimated number of fraudulent payments that your block rules prevented. Stripe uses AI risk scores, calculated by analyzing millions of transactions across the Stripe network, to predict payments with a high probability of being disputed or declined because of fraud, and estimate which of those payments were successfully blocked by your rules.

> If the estimated false positive rate metrics are high, you might consider writing more narrowly targeted block rules or reviewing which payments are covered by the rule, to avoid blocking as many non-fraudulent payments.

Select a block rule to see the following metrics:
![](https://b.stripecdn.com/docs-statics-srv/assets/block-rule-details.5df9a2e8652f228cf61b525a32ef56da.png)

**审核规则**

If you use Radar for Fraud Teams, you can view the following review rules:

- **Payments sent to review**: The total number of payments sent to manual review by your rules.
- **Volume, approved reviews**: The total amount, in your local currency, associated with approved payment reviews.
- **Refund rate**: The percentage of reviews that were refunded.
- **Disputes from approved reviews**: The total number of payments approved in your review, but were ultimately disputed.
- **Volume, disputes from approved reviews**: The total amount, in your local currency, associated with disputes from approved payment reviews.

Select a review rule to see the following metrics:
![](https://b.stripecdn.com/docs-statics-srv/assets/review-rule-details.10851302ef65dee05ffce64f7989528f.png)

#### 查看规则历史

您可以查看 Radar 规则的修改历史。此审计跟踪可帮助您了解规则的创建、编辑、启用或禁用时间，以及团队中哪位用户进行了操作。

To see the activity for a specific rule, go to the [Rules](https://dashboard.stripe.com/radar/rules) tab on the Radar page and click the name of the rule.

**规则活动**日志显示所有修改的摘要。点击具体事件可查看更多详细信息，例如更新前后的完整规则谓词。您只能查看过去 180 天内的规则变更。

定期查看此活动可帮助您将规则修改与其对业务的影响关联起来。

### Regularly monitor your manual review queue 

If your review queue is too large to manage, make sure you have the correct rules in place. If most reviews result in a refund because of fraud, consider additional rules to block payments. If most payments are approved, consider making your review rules more focused.

### 分析您有争议的付款和退款

[Disputes](https://docs.stripe.com/disputes.md) are inherently linked to fraud, so the more you do to reduce fraud, the lower your dispute rate. Check to see if disputed payments share any similar characteristics (for example, from the same locations or of similar amounts). You can also perform this type of investigation by looking at payments that were refunded during a review. If you see trends, you can test and create the appropriate rules. If any payments appear to be fraudulent, refund and report them as fraud to avoid potential disputes.

您还可以使用我们的报告产品、Sigma 和 Data Pipeline 来[查询争议和欺诈数据](https://docs.stripe.com/stripe-data/query-disputes-and-fraud-data.md)。

您可通过管理平台或 API 回应收到的任何争议，我们的[争议文档](https://docs.stripe.com/disputes.md)包含一些关于如何有效提交证据的建议。

### Anticipate large changes to your business that might impact your fraud rate 

If you’re planning any major product releases or changes to your service (for example, a new, high-value product or expanding your service into new countries), you might want to monitor these payments in the beginning. For these kinds of changes, it’s a good practice to set up some review rules so you can examine any new payments. Reviewing these payments and identifying patterns can help you set up new rules to help protect your business from fraud.

## 规则支持多种支付方式 (New)

By default, Radar rules screen payments for cards, ACH, and SEPA Direct Debits for most users. We support the high risk block rule for all of these payment methods. If you use Radar for Fraud Teams or Radar for Platforms, we also support custom rules using the `:payment_method_type:` attribute to write rules that apply only to specific payment methods, for example: `if :payment_method_type: = 'us_bank_account'`. Learn more about [supported attributes](https://docs.stripe.com/radar/rules/supported-attributes.md).

## 构建账户规则

With Radar for Platforms, you can also add and manage account rules from the **Rules** tab on the Radar page in the Dashboard.

#### To add an account rule

1. 点击 **+ 添加规则**。
1. Select the rule type: **Review** or **Payout pause** (which raises a review AND payout pause).
1. 在规则编辑器中，用语法 `{action} if {attribute} {operator} {value}` 构建一个规则，其中：
   - `{action}`: is how Radar responds when the rule criteria is met. This value is pre-populated based on the rule type you selected.
   - `{attribute}`: is the element of the payment to evaluate, such as the amount or card type. Begin typing with `:` to open a list of valid attributes.
   - `{operator}`: is how to compare the attribute to the value, such as `=`, `>`, `!=`, and so on.
   - `{value}`: is the value of the attribute to evaluate.
1. 点击**测试规则**。
1. 如有必要，修改检测到的验证错误。
1. On the **Review new rule** page, view the accounts that would match this rule today to confirm whether you want to enable it.
1. Click **Activate rule** to apply this rule to all existing and future accounts.

Testing account-level rules takes longer than transaction testing, however we recommend testing to avoid unintentionally raising accounts for review or pausing automatic payouts. First, test raising accounts for review behavior. Then, test automatic payout pauses after you’re confident the rule impacts accounts as expected.

## See also

- [3DS rule examples](https://docs.stripe.com/radar/rules.md#request-3d-secure)
- [Continuous fraud management guide](https://stripe.com/guides/improve-fraud-management-with-radar-for-fraud-teams-and-stripe-data)
- [查询争议和欺诈数据](https://docs.stripe.com/stripe-data/query-disputes-and-fraud-data.md)
- [Rules reference](https://docs.stripe.com/radar/rules/reference.md)
- [Supported attributes](https://docs.stripe.com/radar/rules/supported-attributes.md)