Insufficient Funds
The cardholder's account does not have enough available balance to cover the transaction amount. This is one of the most frequent decline reasons, accounting for a significant share of all soft declines.
Why does code 51 occur?
- Account balance lower than transaction amount
- Pending (held) transactions reducing available balance below the required amount
- Credit limit reached on a credit card
- Overdraft protection not enabled or exhausted
Can this transaction be retried?
Yes, code 51 is a soft, retryable decline. You can retry the transaction after a delay of 24-48 hours. Card networks typically allow up to 15 retries (Visa) or 10 retries (Mastercard) per billing cycle for soft declines. Use exponential backoff to space out retries.
What merchants should do
Ask the customer to try a smaller amount, use a different card, or add funds to their account. For subscription billing, retry after 24-48 hours. Consider implementing dunning management to recover failed recurring payments.
What cardholders should do
Check your account balance and add funds, then try again. If you have pending transactions, your available balance may be temporarily lower than your actual balance. You can also use a different card.
Code 51 at a glance
Response Code
51
Name
Insufficient Funds
Category
soft decline
Retryable
Yes — after delay
Related Decline Codes
Do Not Honor
The issuing bank has declined the transaction without specifying a detailed reason. This is the single most common decline code, accounting for a large share of all card declines across the industry.
Exceeds Withdrawal Limit
The transaction amount exceeds the cardholder's daily spending limit, per-transaction limit, or periodic withdrawal limit set by the issuing bank.
Activity Count Limit Exceeded
The cardholder has exceeded the maximum number of transactions allowed within a specific time period (velocity limit). This is a fraud prevention measure.
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Find a SWIFT codeDecline Code 51 FAQ
Frequently asked questions about decline code 51: Insufficient Funds.