Hard-Locking of Auto Populated in GSTR-3B: What Taxpayers Should Know?

The government has introduced hard-locking in GSTR-3B to prevent tax evasion and make the entire GST return filing process more transparent. The change was initiated for the first time via an advisory dated 17th October, 2024. The GST Network made the auto-populated liability fields non-editable from January 2025, which was later postponed. 

In this article, we will discuss what is hard locking of GSTR-3B, the timeline so far and the best practices a business should follow to stay ahead of the curve.

What is Hard-Locking in GSTR-3B?

GSTR-3B is the summary return that taxpayers must file regularly to show details of outward supplies, Input Tax Credit (ITC) claims, tax liability, refunds, etc, recorded on their GSTIN. The details of outward supplies are auto-filled from the already filed GSTR-1/IFF and that of ITC claims are auto-filled from GSTR-2B. 

The government, in order to remove the discrepancies between the data filed by the supplier through GSTR-1/IFF and the recipient via GSTR-2B, introduced hard locking of GSTR-3B by making the auto-populated liability field non-editable, as the first step. Earlier, the taxpayers could manually edit such auto-filled fields in GSTR-3B. With this amendment, any necessary corrections to outward supply details must be made through GSTR-1A before filing GSTR-3B.

Latest Updates

7th June, 2025

GSTN via advisory implemented the restriction of not allowing the taxpayers to file their GSTR-3B after the expiry of a period of three years from the due date of furnishing the said return. The said change will be made effective on the GST portal from July 2025 tax period.

Hard-Locking in GSTR-3B: Timeline

Impact of Hard-Locking on Taxpayers

As the liability in GSTR-3B becomes non-editable, adopting the Invoice Management System (IMS) becomes necessary. Considering GSTR-1A can be filed only once before filing the GSTR-3B of the same tax period, any invoice/credit note rejected by the recipient must be swiftly addressed. 

Not taking action on credit notes rejected by buyers through GSTR-1A will result in a higher output tax liability for that month. Also, with this new amendment in place, businesses won't be able to continue editing GSTR-3B directly for the invoices rejected by the recipient on IMS to reduce the liability.

Hence, businesses must make any changes and amend their incorrectly declared outward supplies in GSTR-1/IFF through GSTR-1A only. Going forward, GSTR-1/1A will be the single source of truth for declaring GST liability in GSTR-3B. Hence, more precision is needed in the GSTR-1 filing. 

Additionally, this change is expected to encourage greater adoption of the IMS functionality among businesses. In due course, its usage will become mandatory once the hard-locking of Input Tax Credit (ITC) is implemented.

How to Handle Errors in Auto-Populated Data?

Considering that GSTR-1/1A will be the source of outward liability going forward, GSTR-3B will just remain a mechanism to discharge liability. 

Hence, all businesses should streamline their GSTR-1 filing process by following below steps: 

1. Review and reconcile e-invoices against the GSTR-1/IFF data carefully before submission.
2. Businesses must regularly check the GST portal for any actions taken by the recipients on IMS.
3. If there’s a mistake or the invoice is rejected by the recipient, use GSTR-1A to amend it in the same tax period. Since the same can be filed only once in a tax period, it must be filed with due precision before filing GSTR-3B.
4. File GSTR-3B only after confirming because GSTR-1A will also be closed after the declaration in the same month. 

Challenges of Hard-Locking

With this move, the government is not only enforcing stricter data integrity and reconciliation between GSTR-1 and GSTR-3B. They are moving towards a monthly tax close in respect of the liability. Hence, businesses must be proactive and timely in reporting and amending outward supplies to avoid incorrect tax liability being locked in. They must validate data in real-time, along with regular vendor communication, to ensure accuracy in the data of GSTR-1 and GSTR-2B.