Common Error Codes for Online Payments (Nets, Stripe, Visa, and Mastercard)

When a customer’s online card payment fails, they might see or report an error code. Here’s a quick overview of the most common error codes – and what they usually mean – across Nets, Stripe, Visa, and Mastercard:

🔴 51 – Insufficient funds

The card does not have enough money to complete the payment.

🔴 05 – Do not honor

A generic decline from the customer’s bank. No specific reason is given. The customer should contact their bank for details.

🔴 14 – Invalid card number

The card number entered is incorrect or not active.

🔴 54 – Expired card

The card’s expiration date has passed.

🔴 57 – Transaction not permitted

The card is blocked from making this type of transaction (e.g., international purchases).

🔴 91 – Issuer or switch is inoperative

The customer’s bank could not be reached (often due to temporary network or system issues).

🔴 96 – System error

A generic processing error happened in the payment network.

Stripe-specific error codes (API error messages)

Stripe uses friendly error messages that map to these common codes:

✅ card_declined – Usually maps to 05 or 57

✅ expired_card – Same as 54

✅ incorrect_number – Same as 14

✅ insufficient_funds – Same as 51

✅ incorrect_cvc – Incorrect security code

✅ processing_error – Same as 96

✅ issuer_unavailable – Same as 91

✅ authentication_required – The payment requires 3D Secure / SCA verification

💡 Helpful tips for customers:

• If the error is card_declined or 05, advise the customer to check with their bank – this is usually out of your control.
• Always double-check that the card number, expiry date, CVC, and amount are correct.
• If you see authentication_required , make sure your checkout supports 3D Secure / SCA.
• For persistent issues, asking the customer to use a different card can help.