I have developed a GST Set-Off Tool in Excel aligned with the GST Advisory dated 19th February 2026. As per this advisory, once the available IGST Input Tax Credit (ITC) has been fully utilized, the GST Portal now permits taxpayers to discharge IGST liability reported in Table 6.1 of GSTR-3B using available CGST and SGST ITC in any sequence.
To incorporate this change, the tool includes a percentage-based set-off mechanism, enabling flexible cross-utilisation of CGST and SGST credits towards IGST liability after exhaustion of IGST ITC. This feature has been structured strictly in accordance with the updated utilisation rules and is applicable from the February 2026 tax period onwards.
The tool is designed to assist in preparation of monthly GSTR-3B tax workings and provides a structured approach for accurate computation of tax liability and ITC utilisation. It also serves as a verification mechanism for tax professionals to cross-check figures relating to tax payable and ITC carry forward.
Additionally, the tool incorporates:
- Opening ITC balances as per the Electronic Credit Ledger on the GST Portal
- Reverse Charge Mechanism (RCM) liability and corresponding ITC claims
- Automated calculation of ITC set-off across IGST, CGST, and SGST
- Carry forward of unutilised ITC
Overall, this tool aims to simplify compliance with the revised ITC utilisation framework and enhance accuracy in GST return preparation.

