The GSTN has issued an Advisory dated 19.02.2026, to inform that Portal has introduced important system enhancements in GSTR-3B from the January 2026 tax period onwards to streamline interest computation, improve reporting accuracy, and align the mechanism with statutory provisions under the CGST Act and Rules.

One of the key changes relates to interest calculation in Table 5.1 of GSTR-3B. The portal will now compute interest after giving the benefit of the minimum cash balance available in the Electronic Cash Ledger (ECL) from the due date of filing till the date of tax payment (offset), in line with the proviso to Section 50 of the CGST Act read with Rule 88B(1) of the CGST Rules. The interest so auto-populated will represent the minimum interest payable and will not be editable downward, though taxpayers may increase it if their self-assessed liability is higher. Further, the GST Portal will auto-populate the “Tax Liability Breakup Table” in GSTR-3B based on the document dates of supplies reported in GSTR-1, GSTR-1A or IFF pertaining to earlier tax periods where tax is discharged in the current return. These values are suggestive in nature and can be modified upward if required.

Another enhancement allows greater flexibility in cross-utilization of Input Tax Credit (ITC), whereby once IGST ITC is fully exhausted, IGST liability may be paid using available CGST and SGST ITC in any sequence. Additionally, in cases of cancelled registrations, if the last applicable GSTR-3B is filed belatedly, the applicable interest will be levied and collected through GSTR-10 (Final Return).

Overall, these changes are intended to improve accuracy in interest computation, facilitate proper tax period reporting, and ensure better compliance with GST law.

The Complete Advisory can be accessed at https://tutorial.gst.gov.in/downloads/news/advisory_on_interest_calculator.pdf