The GST / VAT Audit Trail is part of the GST Return / BAS / VAT Worksheet, and lists all transactions during the period that make up each of the totals on the return, showing the date, details, gross amount and GST amount. The report is broken up into the various categories that appear in the report. Any amount that has a non-standard GST component (i.e. where the GST component is not equal to the standard rate nominated) is highlighted with a hash symbol (#).
The Audit Trail should be printed when you print the final copy of your GST Return / BAS Worksheet / VAT Worksheet, and should be kept on file. It is this report that tax auditors will be most interested in.