Custom Program
Auth Type
Transactions message types

All transactions will be grouped into three basic message types.

Message type Description
Auth (most common type). Card is used for a transaction (MTI X1XX or X2XX). Could be a preauth, auth, ATM, balance inquiry, and so on.
Advice These are MTI XX2X. They might not affect the OTB. This could be force posts, completions, tokenization updates, etc. These cannot be declined. The associations do not allow response codes other that 00 to be returned on these.
Reversal A reversal of a previous auth (MTI X4XX). Should reference a previous transaction, but is not required to.