The option to turn off the Automated Sales Tax feature is unavailable in QuickBooks Online (QBO). If you migrated from Manual Sales Tax into the Automated Sales Tax feature, you can revert it back to the old one.
Select Taxes from the left menu.
Click Sales tax settings at the top right.
At the bottom of the screen, you'll see Want to temporarily switch to the old tax center? Switch here.
Click the here link.
If you have a brand new QBO account with already enabled Automated Sales Tax feature, you can override the automated sales tax calculation on your sales transactions.
However, if the override does not work and you still want to remove the automated feature, I'd suggest contacting our Customer Support Team. They'll further check on what they can do.
Here's how to reach them:
Click the Help menu in the upper-right hand corner of QBO.
Click Contact Us.
Enter a brief description of your concern and click Continue.
Select the option to contact us or receive a callback.