# Idempotency for REST APIs
source: https://developer.mastercard.com/iccp/documentation/api_basics/idempotency/idempotency-rest/index.md

Idempotency is the property of an operation that can be applied multiple times without changing the result beyond its first application. It ensures that the ICCP REST APIs users obtain the same consistent outcome when repeating an operation multiple times.
Idempotency is available for POST endpoint. In order to avail of idempotency, a valid [v4 UUID](https://www.rfc-editor.org/rfc/rfc9562.html#uuidv4) should be included in the request header named Idempotency-Key.

An Idempotency-Key is not required to be provided, and all requests will continue to work as normal without this header, but will not be treated as idempotent.
Note: If an Idempotency-Key is provided, ICCP will consider that any other request to the same endpoint, with the same Idempotency-Key specified within a timeframe of 30 seconds constitutes a duplicate request, and the same response will be provided in this instance.