Root Cause

• Typographical errors: The customer mistyped the card number.
• Invalid card format: The number does not conform to known BIN patterns or is too short/long.
• Test or dummy numbers: Placeholder or mock card numbers used in a live transaction environment.
• Expired or deactivated card: In rare cases, cards no longer active may return as invalid.

Troubleshooting and Solutions

• Inform the customer that the card number they entered is incorrect.
• Ask the customer to double-check the number on their card and re-enter it carefully.
• Ask the customer to use a different card if the issue persists.
• Use account updater wherever applicable to automatically update the card number and avoid card expired failures.