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## Resource: Introduction

## Article: Introduction

## Article Link: https://dev.wix.com/docs/api-reference/app-management/app-billing/billing/introduction.md

## Article Content:

# About the Billing API

The Billing API allows you to charge Wix users for using your app when Wix processes the payments.

> **Note:** If you process payments yourself for a [Partner Billed App](https://dev.wix.com/docs/build-apps/launch-your-app/pricing-and-billing/partner-billed-apps-reporting.md), use the [External Billing Events API](https://dev.wix.com/docs/rest/app-management/app-billing/external-billing-events/introduction.md) instead.

With the Billing API, you can:

- Retrieve the Wix checkout URL for a specific plan. Use it to redirect Wix users from your custom pricing page to Wix checkout.
- Retrieve data about a site's previous purchases for your app.
- Test your app's integration and charge Wix users varying amounts each billing cycle with the [Custom Charges service plugin](https://dev.wix.com/docs/rest/app-management/app-billing/custom-charges-service-plugin/introduction.md).

For more information on how to track data associated with individual app instances, see the [App Instance API](https://dev.wix.com/docs/api-reference/app-management/app-instance/introduction.md).

## Before you begin

It's important to note the following points before starting to code:

- Wix allows you to manage your app's pricing page either through Wix or externally. You can display up to 4 different plans for your app on the Wix pricing page.
- If you manage your app's pricing page on your own servers with an external pricing page, you can still redirect Wix users to the Wix checkout page by using [Get URL](https://dev.wix.com/docs/api-reference/app-management/app-billing/billing/get-url.md).

## Use cases

- [Set up an external pricing page](https://dev.wix.com/docs/api-reference/app-management/app-billing/billing/sample-flows.md#set-up-an-external-pricing-page)

## Terminology

- **App instance**: Specific occurrence of your app on a particular Wix site.
- **Paid plan**: Wix users have installed a version of your app that isn't free of charge. Your app can charge them a one-time payment or on a subscription basis.
- **Wix pricing page**: Wix offers your app an out-of-the-box pricing page that displays up to 4 plans for your app to Wix users.
- **External pricing page**: A custom pricing page that you host on your own servers. You can use an external pricing page with either Wix-processed payments using this Billing API, or partner-processed payments using the [External Billing Events API](https://dev.wix.com/docs/rest/app-management/app-billing/external-billing-events/introduction.md).
- **Partner Billed App**: An app where you process payments through your own payment provider, such as Stripe or PayPal, instead of using Wix checkout. Partner Billed Apps must report billing events using the [External Billing Events API](https://dev.wix.com/docs/rest/app-management/app-billing/external-billing-events/introduction.md).
- **Wix checkout**: The standard Wix checkout page where Wix processes payments.

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