Any chance you can tell us if you set up the code to include sales tax in the line amount?

If so, add up all amounts in the Amount column and see if it adds up to the Subtotal.  Then add the tax at the bottom of the screen below the subtotal and do you get the correct total?

Carla Pierce said:

(so it will not be included in the final posting of the invoice)

Did you check the journal entry from the Report menu to prove this?

Edit: first sentence to make more clear

Thank you for your reply.

There is only one line item for the particular invoice being posted.  I entered "G" (my code for GST), and the 5% calculated in the Tax cell on that line.  It did not also show in the bottom calculation.  I have set up several companies in Sage before, however this is the first time I "started from scratch" (entering my own Chart of Accounts, etc).  Usually, I let Sage do the set up and I adjust accounts as needed, so then this tax thing hasn't been an issue.

So, yes, the amount on the line item matches the subtotal at the bottom.  I did not check the entry from the Report menu, however, I want to be able to see the total GST at the bottom of the screen before posting, so even if it will post properly, that does not rectify my issue.

This sounds like you set up the tax code as tax included or not refundable.

Check your sales tax code setup and see if it matches either of the dialogs in the image below.  The first (G) is I believe what you want and the second (GI) is what I think you might have.

Thank you!  I could swear I had it set up properly initially, and then had no GST at all, but now it appears to be working.  Thanks again!