Sales tax isn't calculating or showing as refundable in the tax report

Note: Verify that your tax codes are set correctly by following How do I set up sales taxes?

1. Go to Setup, Settings.
2. Select Company, Sales Tax, Tax Codes.
3. Select the code you wish to change.
   • Click the magnifying glass or double-click in the Code or Description fields to bring up the tax code detail
   • Verify the rate in the field and update it if necessary. Ensure that GST / HST is set to Refundable
4. Select OK.
5. Close out of the settings. Process a new transaction and verify that the tax now is calculated.

 NOTE: New transactions will show the sales tax as Refundable on the tax report from now on but this won't show on older transactions. If you need the Refundable tax reflected on older transactions, you'll need to reverse and recreate them. 

How do I reverse/ void a transaction?