1.1 Overview
This document describes how a third-party will request to Block a Card, Unblock a Card and Update Card Account from Interswitch. Note that all data formats and response definitions are in conformance with the REST standard.

2 Design
2.1 Overview
For blocking and unblocking a card, the Block and Unblock Card calls on Interswitch CMS API were implemented. For updating card account, an Update card account call on Interswitch CMS API was implemented. The call would first unlink the account(s) currently linked to the card and then link the provided account to the card. The subsequent sections show the message structure for Block Card, Unblock Card and Update Card Account.