Important Update: Enhancements to GSTR-3B Interest Calculation & Filing (Effective January 2026)
The Goods and Services Tax Network (GSTN) has announced significant enhancements to GSTR-3B filing, effective from the January 2026 tax period. These changes are designed to align with the CGST Rules and provide a fairer method for calculating interest on delayed payments.
1. New Interest Computation Formula
The system now provides the benefit of the minimum cash balance available in your Electronic Cash Ledger (ECL) from the return due date until the date of payment. This ensures you are only charged interest on the actual “cash” liability not covered by your existing balance.
Crucial Constraints for Table 5.1:
• Non-Editable Downwards: You cannot decrease the auto-populated interest value.
• Minimum Liability: The system calculates the minimum interest required.
• Manual Upward Revision: If your records suggest a higher liability, you are required to self-assess and amend the value upward.
2. Auto-Population of Tax Liability Breakup
Starting with the January 2026 period, the GST portal will auto-populate the “Tax Liability Breakup Table”.
• Basis: This is generated from the dates of documents (invoices/records) reported in your GSTR-1, GSTR-1A, or IFF that pertain to previous tax periods.
• Purpose: To ensure tax discharged in the current GSTR-3B is correctly attributed to the periods the supplies actually belong to.
3. Flexible ITC Cross-Utilization for IGST
The portal has introduced more flexibility in Table 6.1 (Payment of Tax). Once your available IGST Input Tax Credit (ITC) is completely exhausted, you may now use available CGST and SGST ITC in any sequence to pay your IGST liability.
4. Interest Collection in Final Return (GSTR-10)
For taxpayers whose registrations have been cancelled, if the last applicable GSTR-3B was filed after its due date, the interest for that delay will now be levied and collected via the Final Return (GSTR-10).
