If a retail customer walks in an pays with their credit card, but the cashier made a mistake and entered the wrong amount, can the merchant go back and charge the customer the balance AFTER the customer has left the store? No. According to the Visa Card acceptance guide, “Merchants must NOT alter a sales receipt after the cardholder has signed it and left the establishment. If the cardholder has been undercharged, attempt to contact the cardholder and obtain permission to adjust the receipt so that it reflects the correct amount.”
This issue is outlined in Chargeback Reason Code 80: which includes invalid adjustment.
This question was presented by a building supply company that is largely in the wholesale B2B business, but also has some walk-in retail traffic. The consumer selected their merchandise and an invoice for the materials was issued and presented to the customer. Then the card was charged, but the amount entered was wrong. The customer does not sign the invoice.
The merchant can research information about the transaction in their processors online transaction research, if they offer that capability. Finding the customer can be difficult, but you can try whitepages.com and hope the customer has an unusual name and is from the local area.
The merchant may not be allowed to, and should not try to, charge more than the original authorization, even if they locate the customer. The merchant or the processor may have risk management tools in place to prevent this. If the retailer locates the customer, get permission to create a new transaction which will be key-entered. In the B2B world, ideally, a note with invoice copy is faxed and the customer signs authorization to be billed the balance due. Charging a different amount than the original authorization is an automatic interchange rate downgrade.
On a final note, if the customer DID SIGN THE INVOICE then the merchant MIGHT have a basis to re-bill the customer, provided they had adequate information to do so. Since card issuers generally side with the customer, not the merchant, if the customer disputed the bill, the merchant will likely lose. PLEASE READ THE CURRENT MERCHANT RULES for the specific card association ( MasterCard, Visa etc) for clarification.