You have either selected a tax liability account on a transaction where it's not allowed, or haven't specified a tax rate along with it.

Thanks for posting here in the Community, jrvsconsult. Let me help you with your concern in QuickBooks Online (QBO).

The post you provided seems like an error message you encountered when you're unable to assign a VAT code when using Sales Tax or VAT Liabilities Payable Account. Default tax accounts are used to track VAT and not when creating transactions.

You can record a Journal entry if you want to use the liability account, then match it to your bank statement. Before doing so, you'll want to consult with your accountant or a QuickBooks Certified ProAdvisor to guide you through the process, especially regarding the accounts to use.

Here's how to enter a journal entry:

1. Click on the + New.
2. Select Journal Entry.
3. Fill out the fields to create your journal entry.
4. Then select Save and Close.

For reference, please check this article: Create journal entries in QuickBooks Online.

I've also added these links below for future use:

• How do I set up sales VAT rates and use them on forms?
• Set up and use VAT in QuickBooks Online
• Create or delete a VAT adjustment in QuickBooks Online

Let me know if you have questions or clarifications regarding your VAT concerns in QBO. I'll be right here to help. Have a good one!