Hello, @Dgorm.
To be able to process credit card payments successfully, you have to check your firewall settings to ensure uninterrupted access when using QuickBooks Payments. For your guide, check out these articles:
If possible, you can also try using other devices when processing payments.
In case you have any other payments concern in the future, feel free to read this article: Payments FAQ.
Post again if there's anything you need help with by adding a comment below. I'm a few clicks away to help. Have a good day!
