Authorization Guidelines for American Express Cards

Authorization Guidelines for American Express Cards


American Express requires that merchants accepting its cards obtain an authorization approval for all transactions before processing them. The authorization process is simpler for AmEx cards than it is for Visa or MasterCard, because American Express is the only financial institution involved in authorizing its cardholders’ payments, acting as both an issuer and a processor.


Following is a list of the requirements for obtaining and managing American Express authorizations:

  • Obtaining an authorization approval. Merchants must obtain a six-digit authorization approval code number for all transactions. Each authorization request must:
    • Include the full card account number and
    • Be for the total price of the products or services being sold plus applicable taxes, except for a prepaid card that does not have sufficient funds available to cover that amount. If this is the case, an authorization is required only for the amount of funds used on the prepaid card and the merchant can then follow its own policy on combining payment on prepaid cards with any other payment methods.


    As with Visa and MasterCard authorizations, an American Express authorization approval does not guarantee that the transaction is genuine and that the customer is the actual cardholder. American Express can still issue a chargeback for a transaction that has received an authorization approval code.

  • Thirty-day limit. Merchants are required to obtain a new authorization code for transactions submitted to American Express more than thirty days after the original authorization date.


    For transactions involving products or services that are shipped or provided more than thirty days after an order is placed, merchants must obtain an authorization approval for the charge at the time the order is placed and again at the time the goods or services are shipped or provided to the cardholder.

  • Magnetic-stripe data. Merchants processing card-present transactions electronically are required to transmit the full magnetic stripe data, obtained through swiping the card through a point of sale (POS) terminal, with the authorization request.


    If the magnetic stripe is unreadable or the terminal is down and the merchant is forced to key-enter the transaction data to obtain an authorization, you must take a manual imprint of the card to validate that the card is present. If a manual imprint is not taken for a key-entered transaction, American Express may charge it back.

  • Voice authorizations. As with Visa and MasterCard transactions, if the POS terminal cannot connect to American Express’ system and is unable to obtain an authorization approval electronically, the merchant is required to obtain authorization by calling American Express’ voice authorization center at 1-800-528-2121. Be advised that voice authorizations are substantially more expensive to obtain than electronic ones and cannot be used as supporting evidence in chargeback re-presentments.


Image credit: Wikimedia Commons.

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