DE 38—AUTHORIZATION IDENTIFICATION RESPONSE: This is the authorization code generated when a transaction is approved. In declined transactions, the F38 value is sent empty.
It is alphanumeric, 6 characters long.
What is the authorization code used for?
The authorization code (approval code) sent in F38 is proof that the issuing bank has approved the transaction. The code is printed on the POS receipt along with the transaction and kept in the merchant's records. It is later used to identify the transaction during refund, cancellation, or dispute processes.
Relationship with F39
Fields F38 and F39 are evaluated together. When a transaction is approved, response code 00 is returned in field F39 and an approval code appears in field F38. When a transaction is declined, a code indicating the decline reason is sent in field F39, while field F38 is either left empty or not sent at all.
Manual approval and voice authorization
In some cases, the POS terminal cannot transmit the transaction to the bank online, and the bank directs the merchant to call by phone. In this case, the merchant manually enters into the POS the approval code received from the bank's call center. This is called voice authorization. In these transactions as well, the approval code is kept as proof that the transaction was approved by the bank.
Points to consider in integration
The approval code is generated by the bank's own system. For this reason, different banks may generate codes in different formats. Merchant or integrator systems should not assume that the approval code consists only of digits; the entire field should be stored exactly as received.
