New Interest Calculation in GSTR-3B From January 2026 Onwards: Cash Ledger Balance Now Considered

Starting From Jan 2026 returns, interest calculation will be computed considering the cash ledger balance available from the due date up to the actual payment date. The portal automatically calculates this, exempting interest if minimum cash balance available in the Electronic Cash Ledger of the taxpayer from the due date of return filing until the date of tax payment (offset) in line with the proviso to Rule 88B(1) of the CGST Rules, 2017.

Say for example - Due date to file January 2026 GSTR-3B return is 20 February 2026 - your filing may be late i.e., on 25 February, tax liability is Rs 1 lakh but in the cash ledger from 20 February to 25 February - the same balance is maintained, then no interest applies for those 5 days of delayed filing.

Revised Interest Computation Formula

Interest :

(Net Tax Liability - Minimum Cash Balance in ECL from due date to date of debit) × (No. of days delayed / 365) × Applicable Interest Rate

Where to Check This Auto-Populated Interest?

The interest will be auto-populated in table 5.1 of GSTR-3B.

Is this Interest editable?

Yes, you can edit the same if your own calculation shows higher interest, you must increase or upward the amount in GSTR-3B.

But you are not allowed to edited downward, i.e., decrease the interest amount shown by the system.

The auto-populated interest is only the minimum interest that is required to be paid by the taxpayer.

It may not always be the full or correct amount in every case.

You must check and calculate yourself whether more interest is actually payable. It means the taxpayers needed to self-assess their correct interest liability, and amend the auto-populated values upward, if required.

GST Cancelled but Interest Still Payable?

If the taxpayer's GST registration is cancelled and last applicable GSTR-3B return has been filed after the due date, then the interest applicable on such delayed filing shall be levied and collected through the Final Return i.e., GSTR-10.