I have a suggestion for you to successfully import your invoices in QuickBooks Online (QBO), @TT860. This way, you manage them in your account as soon as possible. 

Before that, please know there's no option to turn it off once activated or use the manual sales tax system. I'd recommend using a third-party app as an alternative solution to eliminate the error and successfully import the invoices.

Here's how: 

1. Go to the Gear icon and choose Import Data.
2. Click the Try this app hyperlink. 
3. Hit the Get app now tab.
4. Follow the on-screen instructions. 

Feel free to read through the following articles below to learn more about how to handle tax payments, use sales tax for specific transactions, and import items in QBO: 

• Manage sales tax payments in QBO.
• Apply sales tax rates to transactions and sales forms in QBO.
• Import products and services into QuickBooks Online

For additional QuickBooks-related concerns, don't hesitate to post them here in the Community. We're always available and willing to lend a hand to your queries. Keep safe always.