GSTR-3B filing to tighten: GSTN to lock monthly tax form from July 2025, changes allowed only via GSTR-1A

Starting July 2025, the GSTN will make the GSTR-3B form non-editable to enhance consistency and reduce revenue leakages. Taxpayers must use GSTR-1A to amend outward supplies before filing GSTR-3B. This shift requires businesses to ensure real-time reconciliation and error correction, placing greater responsibility on internal controls.