# Link in the Mobile Payment Element

Add Link to your native iOS, Android, and React Native apps.

Let your customer check out faster by using [Link](https://docs.stripe.com/payments/link.md) in the [Mobile Payment Element](https://docs.stripe.com/payments/accept-a-payment.md?platform=ios&mobile-ui=payment-element). You can autofill information for any customer already using Link, regardless of whether they initially saved their information in Link with another business. The default Mobile Payment Element integration includes a Link prompt in the card form.

![Link in iOS](images/link/link-in-ios.png)
Add Link to your iOS integration


## Enable Link  

To offer Link in your mobile app:

1. [Integrate the Mobile Payment Element](https://docs.stripe.com/payments/accept-a-payment.md?platform=ios&mobile-ui=payment-element) using the latest version of the Stripe Mobile SDK.
1. Enable Link in your [Payment Method settings](https://dashboard.stripe.com/settings/payment_methods).
1. Enable [Dynamic payment methods](https://docs.stripe.com/payments/payment-methods/dynamic-payment-methods.md) by using the [latest version of the API](https://docs.stripe.com/upgrades.md) or by adding the [automatic_payment_methods](https://docs.stripe.com/api/payment_intents/object.md#payment_intent_object-automatic_payment_methods) parameter when creating your PaymentIntent.
1. (Optional) [Pass in your customer’s email address](#pass-email).

For information about how your payment integration affects Link, see [Link in different payment integrations](https://docs.stripe.com/payments/link/link-payment-integrations.md).

## Pass in a customer’s email address 

Link authenticates a customer using their email address. We recommend prefilling as much information as possible to streamline the checkout process.

To prefill the customer’s name, email address, and phone number, supply `defaultBillingDetails` with your customer information after initializing `PaymentSheet.Configuration`.

```swift
var configuration = PaymentSheet.Configuration()
configuration.defaultBillingDetails.name = "Jenny Rosen"
configuration.defaultBillingDetails.email = "jenny.rosen@example.com"
configuration.defaultBillingDetails.phone = "888-888-8888"
```

To prefill the customer’s name, email address, and phone number, supply `defaultBillingDetails` with your customer information when initializing `PaymentSheet.Configuration`.

```kotlin
let configuration = PaymentSheet.Configuration(
    merchantDisplayName = "Example, Inc.",
    defaultBillingDetails = PaymentSheet.BillingDetails(
        name = "Jenny Rosen",
        email = "jenny.rosen@example.com",
        phone = "888-888-8888"
    )
)
```

```java
PaymentSheet.BillingDetails billingDetails =
  new PaymentSheet.BillingDetails.Builder()
    .name("Jenny Rosen")
    .email("jenny.rosen@example.com")
    .phone("888-888-8888")
    .build();
PaymentSheet.Configuration configuration =
  new PaymentSheet.Configuration.Builder(...)
    .defaultBillingDetails(billingDetails)
    .build();
```

To prefill the customer’s name, email address, and phone number, supply `defaultBillingDetails` with your customer information to `initPaymentSheet`.

```javascript
await initPaymentSheet({
  ...
  defaultBillingDetails: {
    name: 'Jenny Rosen',
    email: 'jenny.rosen@example.com',
    phone: '888-888-8888',
  },
});
```

## Test your integration 

You can create sandbox accounts for Link using any valid email address. When prompted for a one-time passcode, enter `000000`.

## See Also

- [Stripe Mobile SDKs](https://docs.stripe.com/sdks.md#stripe-mobile-sdks)