Thanks for getting back with the Community, AuntieM.

To verify my understanding, are you encountering this message for all cards you try to process or only for these four customers?

Here's a list of some things that can cause issues while trying to process transactions:

• Invalid PIN
• Card not supported
• Invalid Merchant Number
• Invalid merchant account
• Invalid Credit Card Type
• Not an allowed card type
• Merchant account information not recognized
• Your QuickBooks Payments account isn't set up to process the card types you're trying to process. You can check this manually by signing in to the Merchant Service Center, going to Account, then Account Profile.
• If you're trying to process an American Express card which starts with 3785-7, 3785-9, or 3787-3, Intuit merchant accounts won't be able to process these payments electronically. You'll need to request that the customer pays in a different way.

Errors can be caused by an invalid entry from a customer or an employee. They can also be caused by the Internal Server involved in the processing of your transactions.

If you're still unable to process card transactions after performing MirriamM's recommended troubleshooting steps and checking each thing I've mentioned above, I'd recommend getting in touch with our Customer Care team. They'll be able to pull up the account in a secure environment, conduct further research, and discuss why the cards aren't able to be processed and what options you have.

Please feel welcome to send a reply if there's any questions. Have a wonderful day!