GST returns require electronic invoice uploads with ITC auto-population, matching, and automatic reversal of unmatched credits. The GST return framework requires electronic filing with invoice-level uploads, auto-population of recipient returns from suppliers, and an automated matching process that accepts ITC where supplier and recipient data match. Discrepancies, excess or duplicate ITC are communicated and, if not rectified by the supplier, the excess is added to the recipient's output tax liability with interest from the date ITC was availed. Re-claim of reversed ITC is allowed only upon supplier declaration within prescribed timeframes.