I can help you on how to successfully import invoices in QuickBooks Online (QBO), @royalmedicaltran.
Currently, importing invoices will only be successful if you are not using the Sales Tax Center (sales tax codes) yet. Thus, we encounter the error if the feature is already turned on.
There are 3 ways to get your invoices saved/recorded in your QBO account. You can either:
Record invoice manually.
Use third-party application.
Use batch transaction on QBO Advanced.
Meanwhile, here's how to enter the invoices manually one at a time:
1. Click the +New button at the upper left part of the screen.
2. Choose Invoice option under customers. 3. Fill in the necessary details:
Add customer Invoice date Due date Product and Services
4. Select Saveandclose.
To look for a 3rd party app that is suitable for your needs You can go to Apps Center/menu: QuickBooks App Store.