Card data information must be manually keyed into the application when any of the following is true:

• a card is not present
• a card or chip reader is unavailable
• the magnetic stripe or chip is unreadable

For card present transactions, manual entry is discouraged because it usually results in higher transaction fees for the merchant and increases the likelihood of keying errors, which result in delays and/or chargebacks.

For card not present transactions, manual entry is the only method for entering the card number. The use of a Mod 10 check routine (also known as the Luhn algorithm) reduces the number of keying errors. The routine is a checksum formula used to validate the card number that is keyed into your application.