Code 91: Issuer Unavailable

Decline Code 91: What 'Issuer Unavailable' Means & When to Retry

Decline code 91 means the cardholder's issuing bank is temporarily unavailable and cannot respond to the authorization request. This is a system issue, not a card issue and not an account issue. The card may be completely valid. The bank just can't be reached right now. It is a soft decline and in most cases resolves with a short wait and a single retry.

What Does Decline Code 91 Mean?

Every card authorization travels in real time from the merchant's terminal through the payment network to the issuing bank, which checks the account and sends back an approval or decline. Code 91 fires when that last leg of the journey can't complete because the bank's systems are down, overloaded, or temporarily unreachable.

The card being presented has nothing to do with it. The cardholder's account status, available funds, and spending history are irrelevant because the bank never got the chance to evaluate any of them. The authorization request went out and got no response.

Most code 91 declines are brief. Bank system outages and communication interruptions tend to resolve within minutes. An isolated 91 on a single card is usually a momentary blip. A pattern of 91 declines across multiple cards from the same issuer points to a more significant outage on the bank's end.

Is Decline Code 91 a Hard or Soft Decline?

Code 91 is a soft decline. The underlying account isn't blocked, the card isn't flagged, and the bank isn't making a deliberate decision to refuse the transaction. The communication channel is temporarily down. When it comes back up, the same card for the same amount will typically go through without any changes.

The soft classification holds for transient outages. If the same issuer is returning 91 across multiple transactions over an extended period, the bank may be experiencing something more serious. In those cases the practical behavior starts to resemble a hard decline: retrying repeatedly won't help, and the customer may need to use a different card until the bank's systems recover.

Stand-In Processing (STIP): What It Is and When It Applies

Visa and Mastercard both offer a mechanism called Stand-In Processing, or STIP, specifically designed for situations where the issuing bank can't respond to an authorization request.

When a bank is unreachable, the card network itself can step in and make an approval decision based on its own risk rules and the cardholder's history on the network. If STIP approves the transaction, it goes through even though the issuing bank never responded. The bank is notified after the fact.

Not every transaction qualifies for STIP. The network applies its own risk criteria, and high-risk transactions or cards with limited network history may not receive a stand-in approval. Merchants don't control whether STIP applies: if it does, the transaction approves and the code 91 never surfaces. If it doesn't, the 91 comes back and the merchant needs to handle it through the standard path.

The practical takeaway is that STIP exists and is working in the background during outages. Some transactions that would otherwise return a 91 will be approved anyway. The ones that do return a 91 are the ones STIP declined to cover.

How Merchants Should Handle Decline Code 91

1. Wait two to five minutes and retry once. Transient outages typically resolve quickly. A short wait before retrying gives the bank's systems a chance to recover. Retrying immediately on a system that's still down produces the same result.
2. If the retry fails, ask for an alternate payment method. One retry is the appropriate response to a code 91. Continuing to retry the same card after a second failure wastes time and doesn't improve the odds. A different card on a different issuer will likely process normally.
3. Check whether other cards from the same bank are also failing. A single 91 is probably a momentary issue. Multiple 91 declines from the same issuer in a short window suggest the bank is experiencing a broader outage. That context is useful when explaining the situation to the customer.
4. Check your processor's status page if 91 declines are appearing across multiple issuers. If cards from different banks are all returning 91, the issue may be with your gateway or payment network connection rather than any individual issuer.

Frequently Asked Questions About Decline Code 91

Is decline code 91 the customer's fault? No. Code 91 has nothing to do with the cardholder's account, balance, or card status. The issuing bank's systems are simply unavailable at the moment the authorization was attempted. The customer didn't do anything wrong and there's nothing they can do to fix it on their end beyond using a different card or waiting for their bank's systems to come back online.

Should I retry after a code 91 decline? Yes, once, after a short wait. Two to five minutes is enough to give the system time to recover from a transient outage. A single retry after that wait is appropriate. If it fails again, move on to an alternate payment method. Retrying more than once or twice on a persistent outage wastes time and doesn't improve the outcome.

What is stand-in processing and can it help with code 91? Stand-in processing is Visa and Mastercard's mechanism for approving transactions when the issuing bank can't be reached. The network applies its own risk rules and approves the transaction on the bank's behalf. If STIP covers a transaction, the approval comes through and the code 91 never appears. If the transaction doesn't qualify for STIP, the 91 is returned and the standard retry path applies. Merchants don't have direct control over whether STIP applies to a given transaction.

How is code 91 different from code 96 (system error)? Both codes indicate a system-level failure rather than an account or card issue, but they point to different parts of the processing chain. Code 91 specifically means the issuing bank is unavailable: the authorization request made it through the network but couldn't reach the bank. Code 96 is a broader system malfunction that can originate anywhere in the processing chain, including the network or gateway level. Both are soft declines with a retry path, but a code 96 may warrant checking your own gateway status rather than assuming the bank is the source of the issue.

Related Decline Codes

Code 91 sits in the system availability category, separate from card or account issues. These related codes cover adjacent technical failure scenarios:

• Code 96 — System Malfunction. A broader system error that can originate anywhere in the processing chain, not specifically the issuing bank.
• Code 06 — General Error. A catch-all processing error that can overlap with communication failures.
• Code 05 — Do Not Honor. A deliberate bank refusal rather than a system availability issue. No retry path.
• Code 01 — Refer to Issuer. The bank wants cardholder verification before approving. The bank is reachable and responding, unlike a code 91.
• Code 51 — Insufficient Funds. A balance issue on a card whose bank is fully operational.
• Code 12 — Invalid Transaction. A transaction validity error rather than a system availability issue.
• Code 30 — Format Error. A data formatting failure in the transaction request.
• Code 88 — Cryptographic Failure. A chip authentication failure rather than a bank availability issue.