You're unable to turn off the automated sales tax in QuickBooks Online, @Anonymous. I've come to provide additional information and provide a workaround so you can tax-exempt your transactions correctly.

You can set the products and services as nontaxable and set each customer's tax info to tax-exempt if you’re not collecting any sales taxes from them. I'll show you how:

1. Go to the Sales menu and then select Products and Services.
2. Click Edit from the Action column.
3.  From the Sales tax category section, select Non-taxable.
4. Hit Save and close.

Next, navigate to the Sales menu and go to the Customers tab. From there, locate the customer and follow the steps below:

1. Choose a customer profile and click Edit.
2. In the Customer information window, go to the Tax info tab.
3. Make sure to remove the checkmark in the This customer is taxable box.
4. Enter the Exemption details.
5. Click Save.

    

In order to prevent QuickBooks from calculating sales taxes, you can also uncheck the Tax column on all of your sales forms (such as invoices, credit memos, and sales receipts). See the screenshots below:

You’ll want to check out this article to learn how the sales tax feature works: Set up and use automated sales tax in QuickBooks Online.

I'm adding these resources for additional guide on tracking and calculating sales tax:

• Add sales tax categories to your products and services
• Use automated sales tax on an invoice or sales receipt

Don't hesitate to post again here if there's anything else you need to know about the automated sales tax feature. I'd be happy to assist you further. Take care always.