Hello there, @Mark133.
You can resend the invoice to your client. Let me guide you how.
- Go to Sales at the left pane.
- Select Customers.
- Look for the specific customer.
- Under the Transaction List, locate the transaction.
- Click the drop-down arrow under Action.
- Select Send.
If the issue persists, I'd recommend getting in touch with our QuickBooks Payments Team. They'll pull up your account in a secure environment and investigate what's causing the error message when customers pay invoices.
Also, feel free to read our QuickBooks articles in case you need help and related links in the future.
Click the Reply button anytime if you have other questions.
