# Installment Management Service

## Enable Installment plans for cardholders.

\
[Start a Project](https://developer.visa.com/portal/#users/new) \
[API Overview](https://developer.visa.com/capabilities/installment-management-service) \
[API Reference](https://developer.visa.com/capabilities/installment-management-service/reference)

- [Getting Started](https://developer.visa.com/capabilities/installment-management-service/docs-getting-started)
- [Authentication Method](https://developer.visa.com/capabilities/installment-management-service/docs-authentication)
- [Release Notes](https://developer.visa.com/capabilities/installment-management-service/docs-release-notes)
- [Error Codes](https://developer.visa.com/pages/visa-developer-error-codes)
- [API Reference](https://developer.visa.com/capabilities/installment-management-service/reference)
- [Product Terms](https://developer.visa.com/capabilities/installment-management-service/product-terms)

## Installment Management Service Authentication Method

#### X-pay Token

Some Visa Developer APIs require an API Key-Shared Secret Authentication, which Visa refers to as x-pay-token. To invoke an API using x-pay-token, you will need an API Key and a Shared Secret, which is provided via the link below.

Visit the [X-pay Token Guide](https://developer.visa.com/pages/working-with-visa-apis/x-pay-token) to learn more.