Whether you're referring to a sales receipt or a bill, I'll provide insight on how you can proceed.
In QuickBooks Online (QBO), you can assign a VAT code for each line item. Taxes for your transactions can either be exclusive, inclusive or none at all.
See the screenshots below for reference:
If you need to add a custom tax for your QBO company, check out this article: Set up and edit VAT settings, VAT codes, and VAT rates. Scroll down and look for the Add additional tax rate, group rate, or custom tax section.
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