ISO 8583 response codes (field 39)
Field 39 carries the outcome of an authorisation. The two-digit values below are the ISO 8583:1987 convention, which is what card networks and acquirers still send; the 2023 edition of the standard renumbered them to four digits, and individual acquirers remap some values on top of both. Each page says which reading it is describing.
Checked against ISO 8583’s own documentation.
- 00
Approved or completed successfully
The issuer approved the transaction. A field 39 of 00 is the only unambiguous success value in ISO 8583 — every other code is a decline, a referral or an error.
- 01
Refer to card issuer
The issuer will not decide automatically and wants the merchant to call for a voice authorisation. It is not a decline on its own, but at any unattended terminal it is one in practice.
- 03
Invalid merchant
The merchant identifier in the message is not one the issuer or the network recognises. This is a configuration fault on the acquiring side, not a problem with the card.
- 04
Pick up card
The issuer is declining and instructing the merchant to retain the card. It is a hard decline, and the specific reason is deliberately not disclosed to the merchant.
- 05
Do not honour
The issuer refused the transaction and did not say why. It is the most common decline in card processing, and it is deliberately uninformative — 05 is what an issuer sends when it does not want to disclose its reason.
- 12
Invalid transaction
The issuer understood the message but will not accept this kind of transaction on this account. It usually means the processing code, the message type, or the combination of the two is one the issuer does not support.
- 13
Invalid amount
The amount field is malformed or outside what the issuer will accept. Nearly always a formatting fault: ISO 8583 amounts are fixed-length, zero-padded minor units with no decimal point.
- 14
Invalid card number (no such number)
The primary account number does not correspond to an account the issuer knows. The card number is either mistyped, malformed, or routed to an issuer that does not own that range.
- 41
Lost card
The card has been reported lost by the cardholder and the issuer is instructing that it be retained. A final decline that will not succeed on any retry.
- 43
Stolen card
The card has been reported stolen and the issuer is instructing that it be retained. Final, and never worth retrying.
- 51
Not sufficient funds
The account exists and is in good standing but does not have the balance or credit available to cover this transaction. One of the few declines where a later retry can legitimately succeed.
- 54
Expired card
The expiry date on the card has passed, or the date sent does not match what the issuer has on file. A hard decline that only new card details will fix.
- 55
Incorrect PIN
The PIN entered does not match the one on file for the account. In practice, at least as often a PIN block or key problem on the acquiring side as a genuinely mistyped PIN.
- 57
Transaction not permitted to cardholder
The card is valid and the message is well formed, but this cardholder is not allowed to perform this type of transaction. A restriction on the card product, not a shortage of funds.
- 58
Transaction not permitted to terminal
The acquirer or issuer will not accept this transaction type from this terminal or merchant. A configuration fault on the accepting side, so it fails for every card equally.
- 61
Exceeds withdrawal amount limit
The amount is above a per-transaction or per-period ceiling on the account. The card is good and funded; the limit is what refused it.
- 62
Restricted card
The issuer has a restriction on the card that prevents this transaction — commonly a country, merchant-category or account-level block rather than anything about the amount.
- 65
Exceeds withdrawal frequency limit
Too many transactions on this card within the issuer's counting window. It caps the number of transactions rather than their value, which is what separates it from 61.
- 75
Allowable number of PIN tries exceeded
The PIN retry counter on the card or at the issuer has been exhausted. The card is locked for PIN transactions until the cardholder unblocks it.
- 91
Issuer or switch is inoperative
The issuer's authorisation system could not be reached. Nothing is wrong with the card or your message — the decision could not be obtained, so the transaction failed by default.
- 96
System malfunction
Something failed inside the acquirer, network or issuer while processing the message. A generic infrastructure error rather than a decision about the card.