Tip from SmartRetry Suppress automated retries immediately to avoid triggering issuer PIN lockouts on the customer's card. If processing online debit, evaluate whether your gateway supports routing transactions through PINless rails rather than resubmitting the same credential payload.
Mastercard
Mastercard Issuer Response Code 55: Invalid PIN
soft decline
Last updated: September 25, 2026
About 55 - "Invalid PIN"
Key details
- 55
- Issuer Response Codes
- 55
- Invalid PIN
soft decline
What it means
Mastercard issuer response code 55 indicates that the transaction was declined because the customer entered an incorrect Personal Identification Number (PIN). The issuing bank successfully reached the account but blocked the transaction due to the PIN mismatch. It serves as a prompt for the cardholder to correct their entry before they exceed the issuer's allowed attempt limit.
Classification & retryability
softRetryable: conditional
Do not automatically retry the same transaction data. A retry will only succeed if the customer actively re-enters the correct PIN at the terminal. If PIN entry is not possible, request an alternate payment method.
Why does code 55 occur?
- The cardholder accidentally mistyped their PIN on the terminal or point-of-sale device.
- The customer has forgotten their correct PIN and guessed incorrectly during checkout.
- A merchant integration or hardware defect incorrectly passed malformed or encrypted PIN block data to the issuer.
How to solve 55?
For attended point-of-sale transactions, prompt the customer to re-enter their PIN carefully. If they cannot remember the correct PIN, advise them to use an alternative payment method and contact their issuing bank. For card-not-present or recurring online transactions where you cannot collect a PIN, do not attempt automated retries; instead, contact the customer to update their payment details.
Solving as a merchant
Halt automated retries immediately to prevent triggering a hard block for exceeded PIN attempts (such as code 75). Ensure your POS or terminal software clearly displays a 'Wrong PIN' message to the shopper, allowing them a chance to try again safely. If the transaction channel does not support PIN entry, flag the failure and prompt the user for a new payment method.
Solving as a customer
Carefully re-enter your PIN on the terminal pad. If you have forgotten your PIN, use a different credit or debit card to complete the purchase, and contact your issuing bank to request a PIN reset.
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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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