Forgot to add non gst while filing 3B

If you forgot to declare non-GST fuel purchases on your March GSTR-3B filing, don't worry. While you cannot amend the GSTR-3B directly, you should still record the transaction in your Tally software to maintain accurate books. Non-GST inward supplies are not currently part of the GSTR-9 and GSTR-9C reconciliation process, so leaving it out of the GST portal filing for March has no immediate consequences.