I appreciate your time reaching out to us here, samaan-fleurir-t.
Adding a tax value per line item is currently unavailable. You can only add a tax rate for each product/service per line. Then, see the total tax calculated at the bottom right section of the transaction.
I'm adding this article for more details: Manage a tax rate change. To check for other guides and articles, please feel free to browse for a topic in our general support page.
If you have any follow-up questions about sales tax in QuickBooks, please let me know by leaving a comment below. Take care and stay safe.
