Customer is having trouble making payment, system won't allow his payment to be completed

Hi there, adk2988.

My main goal is to ensure your customer can pay you on time.

Before providing any troubleshooting steps, can you share the exact error message your customer encounters when paying invoices? Also, may I know the payment method they're using? Adding these details will help us determine its cause and share an accurate solution to fix this. Sharing a screenshot would be a great help, too.

I'll keep an eye on your response to ensure this gets sorted out. Please don't hesitate to reach back to us. Keep safe!