Is there a way to edit the tax category?

Welcome aboard to the Community, Albreeze.

I'm here to lend a hand with your concern editing the tax category in QuickBooks Online.

If you mean to inactivate your VAT rates in the account, I'll show you how to do so:

1. On the left panel, go to Taxes.
2. Select VAT.
3. Click the Edit VAT drop-down, then choose Edit rates.
4. Untick the small cogwheel icon under the Action column.
5. Click Yes to confirm.
   
   

If this isn't the case, can you share with us more details about your concern? This way, we can provide you with a timely resolution.

Furthermore, I'll be adding this article in case you want to add a sales tax category to your products and services: Add a sales tax category to your products and services.

Additionally, I've added this helpful reference that you can check out about VAT rate the setup process: How do I set up sales GST/VAT rates and use them on forms? (International QBO).

Feel free to drop a comment below if you have any other QBO-related concerns. I'll be more than happy to lend a hand. Have a good one.