I've got you covered, Greg! Let's ensure the credit card payment for your customer in QuickBooks Online is processed quickly and perfectly, with absolutely no issues along the way.

Let's begin by checking your QuickBooks Online account's delivery settings to make sure your customers can pay with a credit card.

Here's how:

1. Use the Gear icon, then go to Account and Settings.
2. Access your Sales tab.
3. Under Invoice Payments, click the pencil icon to edit and specify which payment options you want on email invoices.
   
   
4. From the Sales tab, tap the Online Delivery section to edit.
5. Make sure to choose Online Invoice under Additional email options for invoices.
   
   
6. Click the Save button. Then, hit Done.

Furthermore, it is also essential to ensure that your QuickBooks Payments account remains active and linked to your QBO account. If all is in order, review your payment options by following Step 2 of this article: Take and process payments in QuickBooks Online with QuickBooks Payments.

Nonetheless, can you please ask the customer if they encountered an error when processing their credit card? Sharing the error message or a screenshot would be helpful to identify the issue and most accurate solutions.

I've also included a couple of detailed resources about working with invoices and payment methods, which may come in handy moving forward:

• Take & process payments.
• Add, edit, or disable a credit card.

Our Community space remains open, ready to assist you with any questions about processing payments. We're here to help, so don't hesitate to reach out. Take care!