Tip from SmartRetry Schedule retries around common payroll cycles—such as the 1st and 15th of the month or Friday mornings—rather than firing rapid resubmissions. This gives cardholders time to replenish their balance while protecting your authorization health with issuing banks.
Visa
Visa Issuer Response Code 51: Not Sufficient Funds
soft decline
Last updated: September 25, 2026
About 51 - "Not sufficient funds"
Key details
- 51
- Issuer Response Codes
- 51
- Not sufficient funds
soft decline
What it means
Visa issuer response code 51 indicates that the cardholder's account or available credit limit does not have enough funds to cover the requested transaction amount at the time of authorization. It is a financial decline sent directly by the issuing bank rather than a technical or fraud-related block.
Classification & retryability
softRetryable: conditional
Retries should be spaced to allow time for the customer's balance or credit limit to replenish. While Visa rules allow up to 15 retries in 30 days for this category, best practices require a much smaller, intelligent retry budget (such as aligning with payday cycles). Do not retry immediately.
Why does code 51 occur?
- The cardholder's bank account balance is lower than the requested transaction amount.
- The transaction exceeds the available credit limit on the cardholder's credit card.
- Previous authorization holds have temporarily reduced the available balance on the account.
How to solve 51?
To resolve this decline, the underlying account balance or available credit must increase to cover the requested amount, or the customer must supply a different, fully funded payment method. Immediate, blind resubmissions of the exact same amount without a change in account status will likely result in repeated declines.
Solving as a merchant
Preserve the original decline response and communicate to the customer that the payment failed due to insufficient funds. Prompt them to add funds to their account or provide an alternative payment method. If utilizing automated retry logic, employ a small, spaced retry budget that respects the maximum network limit (15 attempts in 30 days) and stop immediately if an alternate payment method is provided.
Solving as a customer
Check the available balance or credit limit on the account to ensure enough funds exist to complete the purchase. Either add necessary funds, pay down an existing credit balance, or provide a different payment method.
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Author
Kyle Regacho
Find me on LinkedinFocused on payment recovery, decline codes, and authorization optimization at SmartRetry. Helps payment teams turn failed transactions into recovered revenue
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