---
title: Authorisations
slug: authorisations
docTags: 
createdAt: 2025-01-27T15:52:41.008Z
---

An authorisation is used in a card payment to request the approval of the transaction.

An online authorisation exchange is made up of an `AcceptorAuthorisationRequest` message used to request the authorisation of the related transaction and an `AcceptorAuthorisationResponse` message used to provide the outcome of the authorisation.

## Topics

###  [Requests and Responses](docId:8i4QIplbf2PQGO18Wv7Fh)

Contains the structure of AcceptorAuthorisationRequest and AcceptorAuthorisationResponse messages, including message formats, required fields, and example transactions.

### [Single Tap with Online PIN](docId:-eNgYSpRtEbv0Ym0_HHxa)

Contains implementation details for Strong Customer Authentication (SCA) support for contactless transactions that require online PIN verification.

### [Protected Card Data](docId\:okLIGmeGvlkqAOOMaRYpx)

Contains information on how to securely encrypt and transmit card data using the gateway's encryption mechanisms to ensure PCI compliance.