Both Recurly and your payment gateways have fees for each transaction that we attempt to process. To minimize unwanted transaction fees Recurly works to save you money by passing some basic validations before passing the transaction to your payment gateway to attempt to process. This helps to validate the information being submitted has the correct format. Recurly looks at the following:
- Validating that the credit card number is a valid number (ie; passes Luhn check)
- Validating that the CVV format matches the card type selected
- Validating a future expiration date format
- Validating the zip code format (when country code is supplied, for limited countries)
- Validate the entry of address information based on site-level address requirements.
This doesn't prevent declines entirely but helps to reduce them greatly by ensuring the billing information submitted is formatted correctly and contains the needed information to process.