Thanks for responding. I understand it is per county but, if the invoice knows the county, can calculate sales tax for that invoice in that county, could it not also do it line by line as well?
I can see the importance of showing the tax amount per item on your invoices. However, this is currently not an option in QuickBooks. You can try to look for a third-party app that is capable of creating invoices in this format.
We're just right here if you have additional questions.
I can see how essential this option to you and your customer. However, as mentioned by my colleagues, showing the sales tax per item in your invoice isn't available in QuickBooks Online.
You may consider looking for a third-party app that you can integrate with QuickBooks to create an invoice with this setup.
I've also added these great Community resources in working with sales tax in QuickBooks Online: