If you do not use the US version of QuickBoooks Online (ie. your version is for the Canada, Australia, UK or India) then you should be aware of the following items regarding how sales tax is handled by the QuickBooks Online Global version.
Sales Tax Override
When you enter your QuickBooks Sync Settings you will need to select your Sales Tax Account if you intend to include tax on your invoices. This tax account will have a rate set in your QuickBooks account. If you generate an invoice that uses a different sales tax rate, QuickBooks will override the sales tax in Teachworks and calculate it using the sales tax rate in QuickBooks.
Tax Calculated on Line Items
Unlike the US version of QuickBooks and Teachworks, the Global version of QuickBooks calculates tax separately for each line item on the invoice instead of on the invoice total. When you sync an invoice to QuickBooks, QuickBooks will recalculate the sales tax for each line item and overrides the sales tax total. Due to rounding sales tax for each line, the sales tax total for an invoice in QuickBooks may be a few cents higher or lower than the sales tax total on the invoice in Teachworks.
You can update the Invoice Sales Tax by Line Item setting on your Account Settings page so that your invoices generated in Teachworks will also calculate sales tax by line item.
When QuickBooks calculates inclusive tax on line items, their method can result in rounding to a different cent, which results in a different line total than the original invoice in Teachworks. For consistency, we recommend users of the Global version of QuickBooks Online use the Tax Exclusive treatment.