# Adds pending invoice item interval parameter to update Checkout Sessions

## What’s new

Adds the [pending_invoice_item_interval](https://docs.stripe.com/api/checkout/sessions/update.md?api-version=2026-03-25.preview#update_checkout_session-subscription_data-pending_invoice_item_interval) parameter to the [update CheckoutSession](https://docs.stripe.com/api/checkout/sessions/update.md?api-version=2026-03-25.preview) endpoint. Use it to specify the billing frequency for [pending invoice items](https://docs.stripe.com/billing/invoices/subscription.md#Customize) when using [Checkout](https://docs.stripe.com/payments/checkout.md) with [subscriptions](https://docs.stripe.com/subscriptions.md). You can specify `day`, `week`, `month`, or `year`.

## Impact

You can now configure the billing interval for pending invoice items when updating subscription-based payments in [Checkout Sessions](https://docs.stripe.com/api/checkout/sessions.md?api-version=2026-03-25.preview). That allows you to invoice pending items on a different schedule than the subscription cycle without needing to [update the Subscription](https://docs.stripe.com/api/subscriptions/update.md?api-version=2026-03-25.preview#update_subscription-pending_invoice_item_interval) after the Checkout Session completes.

## Changes

#### REST API

| Parameter | Change | Resources or endpoints |
| --- | --- | --- |
| `pending_invoice_item_interval` | Added | [Checkout.Session#update.subscription_data](/api/checkout/sessions/update?api-version=2026-03-25.preview#update_checkout_session-subscription_data) |

#### Ruby

| Parameter | Change | Resources or methods |
| --- | --- | --- |
| `pending_invoice_item_interval` | Added | [Checkout::SessionUpdateParams::SubscriptionDatum](/api/checkout/sessions/update?api-version=2026-03-25.preview#update_checkout_session-subscription_data) |

#### Python

| Parameter | Change | Resources or methods |
| --- | --- | --- |
| `pending_invoice_item_interval` | Added | [checkout.SessionModifyParamsSubscriptionDatum](/api/checkout/sessions/update?api-version=2026-03-25.preview#update_checkout_session-subscription_data) |

#### PHP

| Parameter | Change | Resources or methods |
| --- | --- | --- |
| `pending_invoice_item_interval` | Added | [Checkout\Session.update().$params.subscription_datum](/api/checkout/sessions/update?api-version=2026-03-25.preview#update_checkout_session-subscription_data) |

#### Java

| Parameter | Change | Resources or methods |
| --- | --- | --- |
| `pendingInvoiceItemInterval` | Added | [checkout.SessionUpdateParams.subscription_data](/api/checkout/sessions/update?api-version=2026-03-25.preview#update_checkout_session-subscription_data) |

#### Node.js

| Parameter | Change | Resources or methods |
| --- | --- | --- |
| `pending_invoice_item_interval` | Added | [Checkout.SessionUpdateParams.subscription_data](/api/checkout/sessions/update?api-version=2026-03-25.preview#update_checkout_session-subscription_data) |

#### Go

This change does not affect the Go SDK.

#### .NET

This change does not affect the .NET SDK.

## Upgrade

#### REST API

1. [View your current API version](https://docs.stripe.com/upgrades.md#view-your-api-version-and-the-latest-available-upgrade-in-workbench) in Workbench.
2. If you use an SDK, upgrade to the corresponding SDK version for this API version.
   - If you don’t use an SDK, update your [API requests](https://docs.stripe.com/api/versioning.md) to include `Stripe-Version: 2026-03-25.preview`
3. Upgrade the API version used for [webhook endpoints](https://docs.stripe.com/webhooks/versioning.md).
4. [Test your integration](https://docs.stripe.com/testing.md) against the new version.
5. If you use Connect, [test your Connect integration](https://docs.stripe.com/connect/testing.md).
6. In Workbench, [perform the upgrade](https://docs.stripe.com/upgrades.md#perform-the-upgrade). You can [roll back the version](https://docs.stripe.com/upgrades.md#roll-back-your-api-version) for 72 hours.

Learn more about [Stripe API upgrades](https://docs.stripe.com/upgrades.md).

#### Ruby

1. [View your current API version](https://docs.stripe.com/upgrades.md#view-your-api-version-and-the-latest-available-upgrade-in-workbench) in Workbench.
2. Upgrade your Ruby SDK to the latest version.
3. Upgrade the API version used for [webhook endpoints](https://docs.stripe.com/webhooks/versioning.md).
4. [Test your integration](https://docs.stripe.com/testing.md) against the new version.
5. If you use Connect, [test your Connect integration](https://docs.stripe.com/connect/testing.md).
6. In Workbench, [perform the upgrade](https://docs.stripe.com/upgrades.md#perform-the-upgrade). You can [roll back the version](https://docs.stripe.com/upgrades.md#roll-back-your-api-version) for 72 hours.

Learn more about [Stripe API upgrades](https://docs.stripe.com/upgrades.md).

#### Python

1. [View your current API version](https://docs.stripe.com/upgrades.md#view-your-api-version-and-the-latest-available-upgrade-in-workbench) in Workbench.
2. Upgrade your Python SDK to the latest version.
3. Upgrade the API version used for [webhook endpoints](https://docs.stripe.com/webhooks/versioning.md).
4. [Test your integration](https://docs.stripe.com/testing.md) against the new version.
5. If you use Connect, [test your Connect integration](https://docs.stripe.com/connect/testing.md).
6. In Workbench, [perform the upgrade](https://docs.stripe.com/upgrades.md#perform-the-upgrade). You can [roll back the version](https://docs.stripe.com/upgrades.md#roll-back-your-api-version) for 72 hours.

Learn more about [Stripe API upgrades](https://docs.stripe.com/upgrades.md).

#### PHP

1. [View your current API version](https://docs.stripe.com/upgrades.md#view-your-api-version-and-the-latest-available-upgrade-in-workbench) in Workbench.
2. Upgrade your PHP SDK to the latest version.
3. Upgrade the API version used for [webhook endpoints](https://docs.stripe.com/webhooks/versioning.md).
4. [Test your integration](https://docs.stripe.com/testing.md) against the new version.
5. If you use Connect, [test your Connect integration](https://docs.stripe.com/connect/testing.md).
6. In Workbench, [perform the upgrade](https://docs.stripe.com/upgrades.md#perform-the-upgrade). You can [roll back the version](https://docs.stripe.com/upgrades.md#roll-back-your-api-version) for 72 hours.

Learn more about [Stripe API upgrades](https://docs.stripe.com/upgrades.md).

#### Java

1. [View your current API version](https://docs.stripe.com/upgrades.md#view-your-api-version-and-the-latest-available-upgrade-in-workbench) in Workbench.
2. Upgrade your Java SDK to the latest version.
3. Upgrade the API version used for [webhook endpoints](https://docs.stripe.com/webhooks/versioning.md).
4. [Test your integration](https://docs.stripe.com/testing.md) against the new version.
5. If you use Connect, [test your Connect integration](https://docs.stripe.com/connect/testing.md).
6. In Workbench, [perform the upgrade](https://docs.stripe.com/upgrades.md#perform-the-upgrade). You can [roll back the version](https://docs.stripe.com/upgrades.md#roll-back-your-api-version) for 72 hours.

Learn more about [Stripe API upgrades](https://docs.stripe.com/upgrades.md).

#### Node.js

1. [View your current API version](https://docs.stripe.com/upgrades.md#view-your-api-version-and-the-latest-available-upgrade-in-workbench) in Workbench.
2. Upgrade your Node SDK to the latest version.
3. Upgrade the API version used for [webhook endpoints](https://docs.stripe.com/webhooks/versioning.md).
4. [Test your integration](https://docs.stripe.com/testing.md) against the new version.
5. If you use Connect, [test your Connect integration](https://docs.stripe.com/connect/testing.md).
6. In Workbench, [perform the upgrade](https://docs.stripe.com/upgrades.md#perform-the-upgrade). You can [roll back the version](https://docs.stripe.com/upgrades.md#roll-back-your-api-version) for 72 hours.

Learn more about [Stripe API upgrades](https://docs.stripe.com/upgrades.md).

#### Go

1. [View your current API version](https://docs.stripe.com/upgrades.md#view-your-api-version-and-the-latest-available-upgrade-in-workbench) in Workbench.
2. Upgrade your Go SDK to the latest version.
3. Upgrade the API version used for [webhook endpoints](https://docs.stripe.com/webhooks/versioning.md).
4. [Test your integration](https://docs.stripe.com/testing.md) against the new version.
5. If you use Connect, [test your Connect integration](https://docs.stripe.com/connect/testing.md).
6. In Workbench, [perform the upgrade](https://docs.stripe.com/upgrades.md#perform-the-upgrade). You can [roll back the version](https://docs.stripe.com/upgrades.md#roll-back-your-api-version) for 72 hours.

Learn more about [Stripe API upgrades](https://docs.stripe.com/upgrades.md).

#### .NET

1. [View your current API version](https://docs.stripe.com/upgrades.md#view-your-api-version-and-the-latest-available-upgrade-in-workbench) in Workbench.
2. Upgrade your .NET SDK to the latest version.
3. Upgrade the API version used for [webhook endpoints](https://docs.stripe.com/webhooks/versioning.md).
4. [Test your integration](https://docs.stripe.com/testing.md) against the new version.
5. If you use Connect, [test your Connect integration](https://docs.stripe.com/connect/testing.md).
6. In Workbench, [perform the upgrade](https://docs.stripe.com/upgrades.md#perform-the-upgrade). You can [roll back the version](https://docs.stripe.com/upgrades.md#roll-back-your-api-version) for 72 hours.

Learn more about [Stripe API upgrades](https://docs.stripe.com/upgrades.md).