How to change the total tax amount for a document on Sage 300 Purchase Orders


  1. Click the Taxes tab on the the document entry screen.
  2. Edit the vendor tax class if necessary, and then click the Calc. Taxes button to see the results of the change.
  3. To manually change the total tax amount for the vendor, enter new tax totals in the Tax Amount column.
  4. Purchase Orders distributes the updated tax amounts when you move to another tab or post the transaction.