Tried to add my first client, entered my card details and it came back with payment validation error
Let's get this problem resolved so you can successfully add your payment info, @whittalsquared-g.
To isolate the issue, let's first check if this error is caused by outdated data in your browser's cache. To do so, let's begin with accessing your QuickBooks Online (QBO) account using an incognito browser and enter your card details again.
Below are the shortcut keys you can use to open one:
Google Chrome and Microsoft Edge press: Ctrl + Shift + N
Mozilla Firefox : Ctrl + Shift + P
Safari: Hold down Command + Shift + N
If this works, I recommend clearing the cache of your regular browser to improve its background processes and to have a clean slate. If the same issue persists, you can use another supported browser to enter your card details. In QBO, to prevent errors performing your task, we have to ensure that your system meets the minimum requirements to run the program.