<h1>Interest computation and auto-populated tax liability in GSTR-3B updated to allow cash ledger offset; taxpayers must verify amounts.</h1> From the January 2026 tax period, portal interest calculation for delayed filing of GSTR-3B is revised to allow offset by the minimum cash balance in the Electronic Cash Ledger from the return due date to payment date, and the interest will be auto-populated using a specified formula; taxpayers cannot reduce the system-computed value but must self-assess and may increase it. The portal will auto-populate a tax liability breakup in GSTR-3B for supplies of earlier periods paid in the current period, and will permit suggestive cross-utilization of ITC between CGST and SGST after IGST ITC is exhausted. Interest on late final returns will be collected via GSTR-10.