Response Code 91: Issuer unavailable

SOFT DECLINE RETRIABLE ISO 8583 FIELD 39

The issuer's system is down or unreachable. The transaction was never evaluated.

What Does Code 91 Mean?

Response code 91 means the card network could not reach the issuing bank's authorization system. The transaction was never evaluated: the issuer didn't decline it, they simply weren't available to process it. This is the digital equivalent of a phone line being busy.

Code 91 is one of the most reliably recoverable decline codes because the failure has nothing to do with the card, the cardholder, or the merchant. It's an infrastructure problem on the issuer's side. Issuer outages are typically short (minutes to hours), so a retry within 30 minutes to an hour has a high probability of success.

If you see code 91 persistently for cards from the same issuer, it usually indicates a regional bank having system issues. Check DownDetector or similar services for the bank in question.

Should You Retry?

Recovery Guidance

Very high recovery potential. The card was never evaluated, so this is pure infrastructure. Fast retry is safe here.

Common Causes

Issuer's authorization system is temporarily offline
Network connectivity issue between the card network and the issuer
Issuer undergoing scheduled maintenance
Regional bank system outage

Network Behavior

The same response code can mean different things depending on the card network. Here is how each network treats Code 91:

Network	Retry?	Limit	Notes
Visa	Yes	15 attempts in 30 days	Visa Category 2 (issuer cannot approve at this time). Very high recovery potential since the card itself was never evaluated. The issuer just was not reachable.
Mastercard MAC 24	Yes	10/day, 35/month	Often accompanied by MAC 24 (retry after 1 hour). This is a pure infrastructure failure. Issuer outages typically resolve within minutes to hours.
Amex	Yes		Since Amex is both network and issuer, Code 91 from Amex means their own system is having issues. These outages tend to be brief and well-publicized.
Discover	Yes		Standard infrastructure failure. Retry within 30-60 minutes for best results.

Platform Mappings

This code surfaces under different names depending on the payment platform:

ISO 8583	`91` - Issuer unavailable
Stripe	`issuer_not_available`

Related Decline Codes

Related Guides

See This Code in Action

Watch how response code 91 flows through a complete ISO 8583 authorization lifecycle.

Open Transaction Simulator