None of Quik Invoice Plus (DOS), Quik Invoice for Windows, nor Adagio Invoices have a year end processing procedure. You are not required to delete any open batches or purge history. Because Quik Invoice (Adagio Invoices) requires Receivables, the Year End processing for customers would be done through AR. The only thing you may wish to do in Invoices is to print the batch status report, and reset the batch number to 1.

As for your GST question, which Quik Invoice are you using (DOS, Windows, Adagio), and what version? In somewhat older versions, there was a problem if you entered invoices in a very specific way, and this has been fixed in more current versions. For the invoice that has the wrong tax, you can fix it by performing a 'trick'. On the Bill To screen, change the Tax Status (0-9) to another choice, then change it back. This will force Quik Invoice to recalculate taxes, and you should find the correct amount of GST.

Regards,
Softrak Support