Issuer application data

The Issuer Application Data (IAD) acts as an extensible channel for issuers to embed additional context into a transaction without altering the core Europay, Mastercard, and Visa (EMV) protocol. The data structure consists of an 18-byte Mastercard reserved block and a 14-byte wallet proprietary block, as the following figure shows.

As the MPP, you have control over the 10-byte wallet extended data block. Use the setCustomData API to write your custom payload, such as order numbers or payment methods, into this space.

Note: The wallet extended data must be exactly 10 bytes. If your custom data is less than 10 bytes, right-pad the value with zeros to reach the required length.