Use this window to manage the VAT tax.

By default, the VAT tax is calculated automatically based on the VAT tax code, its tax percent, invoice amount before tax and the retention amount on the invoice. You may elect to override the calculation; for example, when the vendor invoice includes a different tax amount. This window is accessible from the VAT tax amount field in the heading of the main screen, and opens automatically when you type an amount into that field (the invoice must be set to 'Calculated' and the amount entered must be different from the calculation).

This window will alert you if your Entered tax does not match the Calculated tax, and a Tax entry option let's you choose to keep either the 'Entered' or 'Calculated' number. When the 'Entered 'or 'Calculated' values are edited, any dependent values will automatically recalculate.

You can only enter a negative amount if the calculation of 'Total tax' will result in zero or a positive value. This scenario can only occur when the transaction is a subcontract invoice containing a negative retention adjustment.