When processing a commercial credit card, you can provide additional data about the sale, which includes sales tax amount and sometimes customer code. This information is used by the cardholder's company for bookkeeping purposes.
For most card types, Merchant Service for QuickBooks is able to detect that the card is a commercial card (based on the card number) and prompts you to enter the additional information.
Merchant Service for QuickBooks does not support the entry of additional information for American Express commercial cards.
What is the Merchant Service for QuickBooks?