The Statutory ITC Set-Off Hierarchy
Section 49(5) of the CGST Act read with Rule 88A prescribes a fixed order in which accumulated input tax credit must be utilized. This is not optional: the GST portal itself enforces this sequence and rejects any manual override that violates it.
IGST credit must first be fully exhausted before any CGST or SGST credit can be used. Rule 88A (inserted with retrospective effect from 1 February 2019) additionally permits IGST credit to be applied against CGST and SGST liability in any order or proportion the taxpayer chooses, as long as the entire IGST credit balance is utilized first.
Only after IGST credit is exhausted can CGST credit be used against CGST liability (and any residual against IGST liability), and SGST/UTGST credit be used against SGST/UTGST liability (and any residual against IGST liability). Critically, CGST credit can never be used to pay SGST liability, and SGST credit can never be used to pay CGST liability — cross-utilization between CGST and SGST is expressly barred.
Getting this sequence wrong leads to either blocked credit sitting idle in one head while cash is paid unnecessarily from another, or an incorrect return that will not match the portal's own computation. This engine replicates the exact GSTN set-off logic so the output matches GSTR-3B Table 6.1.
Worked Example: Utilization Order for a Mixed Credit Ledger
A taxpayer has output liability of IGST ₹40,000, CGST ₹30,000, SGST ₹30,000, and available ITC of IGST ₹50,000, CGST ₹10,000, SGST ₹10,000.
Frequently Asked Questions (FAQs)
Can I choose to use CGST credit before IGST credit to save cash outflow?
No. Rule 88A and the portal logic mandate that the entire available IGST credit be utilized first before any CGST or SGST credit is applied, regardless of which sequence would be more cash-efficient for the taxpayer.
Can CGST input credit be used to pay SGST output liability?
No. Section 49(5)(e) and (f) expressly prohibit cross-utilization between CGST and SGST/UTGST credit. Each can only offset its own head of liability, with any residual first flowing to IGST liability.
What is Rule 88A and when did it take effect?
Rule 88A was inserted into the CGST Rules with retrospective effect from 1 February 2019. It gives taxpayers flexibility to apply IGST credit against CGST and SGST liability in any proportion, but only after clarifying that the full IGST credit balance must be exhausted before CGST/SGST credit is touched.
Does the GST portal enforce this order automatically in GSTR-3B?
Yes. Table 6.1 of GSTR-3B on the GST portal auto-populates the set-off in this exact statutory sequence; taxpayers can adjust amounts within the permitted flexibility of Rule 88A but cannot violate the IGST-first rule or the CGST-SGST cross-utilization bar.
What happens to unutilized ITC after set-off?
Any ITC balance remaining after the mandatory set-off carries forward in the Electronic Credit Ledger to the next tax period and remains available for future utilization, subject to the time limits under Section 16(4) for claiming the credit in the first place.