Auto-Populated Data in GSTR-3B to Be Hard Locked

Introduction

Starting with the July 2025 tax period, the Government will implement hard-locking of auto-populated liability fields in GSTR-3B, making these fields completely non-editable. This marks a major shift in GST compliance.

Under this new regime, businesses will no longer be able to manually adjust values auto-populated from GSTR-1 and GSTR-2B while filing GSTR-3B. Any corrections must now be made only through GSTR-1 or the newly introduced GSTR-1A, before GSTR-3B is filed.

This article explains:

What hard-locking means
Which GSTR-3B fields are impacted
The implementation timeline
Practical steps businesses must take to remain compliant and avoid mismatches

What Is GSTR-3B?

GSTR-3B is a monthly self-declared summary return that must be filed by all registered GST taxpayers, except composition dealers, non-resident taxable persons, and a few others.

It captures summary details of:

Outward supplies (sales)
Input Tax Credit (ITC)
Tax liabilities
Tax payments

Until now, taxpayers could edit auto-populated figures in GSTR-3B sourced from GSTR-1 (outward supplies) and GSTR-2B (ITC). While this flexibility allowed last-minute adjustments, it also resulted in frequent mismatches and reconciliation issues, drawing scrutiny from tax authorities.

What Is Hard-Locking in GSTR-3B?

Hard-locking means that specific auto-populated fields in GSTR-3B—primarily outward tax liability fields—become completely non-editable once populated by the system.

If errors are found, corrections must be made through:

GSTR-1 (for outward supply amendments)
GSTR-1A (for correcting invoices or credit notes rejected by recipients)

This change strengthens reliance on source returns and aims to eliminate inconsistencies between supplier and recipient filings.

Why Has the Government Introduced Hard-Locking?

The primary objective is to ensure:

Outward tax liability in GSTR-3B exactly matches GSTR-1
ITC claimed matches eligible credit in GSTR-2B

By removing manual intervention, the system enforces cleaner data, improves reconciliation, and supports the government’s vision of a single source of truth in GST reporting.

Which GSTR-3B Fields Are Hard-Locked?

Hard-locking applies to outward liability fields auto-populated from GSTR-1, including:

Table 3.1(a) – Taxable outward supplies (other than zero-rated, nil-rated, and exempt)
Table 3.1(b) – Zero-rated outward supplies (e.g., exports)
Table 3.1(c) & 3.1(e) – Nil-rated, exempt, and non-GST outward supplies
Table 3.2 – Inter-State supplies to unregistered persons

Once populated, these values cannot be edited in GSTR-3B. Any corrections must be completed through GSTR-1 or GSTR-1A before filing GSTR-3B.

Latest Update: Table 3.2 Now Non-Editable

As per the GSTN advisory dated 19 July 2025, Table 3.2 of GSTR-3B—which reports inter-State supplies to unregistered persons, composition taxpayers, and UIN holders—will also become non-editable from the July 2025 tax period.

Earlier, taxpayers could manually adjust this table. Going forward:

Values will auto-populate from GSTR-1 or IFF
GSTR-3B must be filed without any modification
Corrections must be made via GSTR-1A (before filing GSTR-3B) or through amendments in future GSTR-1 returns

👉 Businesses must now exercise extreme caution while reporting inter-State outward supplies in GSTR-1/IFF.

Implementation Timeline

Effective Tax Period: July 2025
First Impacted Return: GSTR-3B filed in August 2025

Key Government Announcements

17 October 2024: Hard-locking announced to curb mismatches
27 January 2025: Implementation deferred based on stakeholder feedback
7 June 2025: GSTN confirmed enforcement from July 2025 tax period

What Businesses Need to Do Now

With auto-populated GSTR-3B fields becoming non-editable, proactive compliance is critical.

1. Reconcile GSTR-1 Data Thoroughly

Ensure all invoices (e-invoices and manual) are accurately reported
Validate GSTINs, invoice values, tax rates, and HSN/SAC codes

2. Monitor Buyer Actions via IMS

Track invoice acceptances and rejections in real time
Address rejected invoices or credit notes immediately

Note: Amendments in GSTR-1 can be made up to 30 November of the following financial year or before filing the annual return, whichever is earlier.

3. Use GSTR-1A Carefully

GSTR-1A is the only opportunity to correct outward supply data before GSTR-3B filing
It can be filed only once per tax period, so accuracy is essential

4. File GSTR-3B Only After Final Reconciliation

Verify auto-populated values after GSTR-1A
File GSTR-3B only when all figures align—no edits are allowed later

5. Train Teams and Update ERP Systems

Educate accounting and tax teams on the new workflow
Integrate invoice-level validation and reconciliation into ERP systems

How to Handle Errors Under the Hard-Locking Regime

Since GSTR-1 and GSTR-1A are now the sole sources of outward tax liability, GSTR-3B effectively becomes a locked summary return used only for tax payment.

Best Practices:

Reconcile before reporting – Errors in GSTR-1 will flow directly into GSTR-3B
Monitor IMS regularly – Act quickly on rejected invoices or credit notes
Use GSTR-1A with precision – Only one chance per month
File GSTR-3B last – Only after all corrections are complete

Practical Scenarios

Scenario 1: Error in June 2025 Invoices

If an error is identified after filing June 2025 GSTR-1 but before GSTR-3B:

Use GSTR-1A for June 2025
Corrections will reflect in the auto-populated, locked GSTR-3B

Scenario 2: Credit Note Rejected for May 2025

If a May credit note is rejected in IMS during June:

Additional liability flows into July 2025 GSTR-3B
Correction must be made through July 2025 GSTR-1 amendment section
GSTR-1A cannot be used, as it applies only to July invoices

Scenario 3: Supplier–Recipient Disagreement

If a recipient rejects a correct invoice:

Supplier must still amend GSTR-1 in later periods to align data
Failure may lead to ITC denial or scrutiny notices
Timely communication with recipients is essential

Key Takeaways

GSTR-1 is now the single source of truth for outward supplies
GSTR-2B remains the basis for ITC claims
GSTR-1A is critical for resolving issues before GSTR-3B
GSTR-3B is now a locked, system-generated summary return

Need Help with GSTR-3B Hard-Locking?

With GST compliance becoming more stringent, accuracy and timing are more important than ever. Auriga Accounting pvt. ltd. helps businesses stay compliant through expert support, smart automation, and seamless GST return management—from GSTR-1 and IMS handling to error-free GSTR-3B filing.

About the Author

Ravi

“Ravi simplifies complex legal requirements into clear, practical guidance, empowering entrepreneurs to remain compliant and grow sustainable businesses with confidence.”