GSTN had implemented a system validation on the GST Portal in May 2025, mandating that all due GSTR-1 and GSTR-3B returns (or other specific returns for certain taxpayer types) must be filed before a refund application can be submitted. This new validation caused issues for Quarterly Return Monthly Payment (QRMP) scheme taxpayers, as the system did not correctly recognize invoices furnished through the Invoice Furnishing Facility (IFF) for the initial two months of a quarter (M1 and M2). This oversight prevented QRMP taxpayers from filing their refund applications, particularly when attempting to do so between quarters. GSTN has since resolved this technical problem. However, invoices furnished via IFF that do not yet have a filed GSTR-3B should not be included in the refund claim.