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Effective: February 2026 Tax Period Onwards  |  GSTR-3B (Table 6.1) 

  GSTN Advisory 647 & 649  |  Published: March 2026


 Executive Summary

The GST Network (GSTN) has introduced a landmark enhancement to Input Tax Credit (ITC) utilisation

effective from the February 2026 return period. Under GSTN Advisories 647 and 649, taxpayers filing

GSTR-3B now have the flexibility to use CGST or SGST Input Tax Credit in any order to discharge IGST

liabilities — after fully exhausting IGST credit. This removes a long-standing compliance pain point

that forced cash payments even when sufficient credit was available in another tax head.

 

1.  Background & Problem Statement


 

Under the original GST framework, ITC utilisation followed a rigid mandatory hierarchy. Taxpayers had no choice in how credits were applied — the portal automatically enforced a fixed sequence, which frequently led to practical difficulties:

 

Tax Head Old Mandatory Sequence Common Problem
IGST Liability IGST ITC first (mandatory) Fine — logical
Remaining IGST CGST ITC (forced next) Even if SGST balance was higher
SGST Liability SGST ITC first Credit often trapped unused
CGST Liability CGST ITC first Cash paid unnecessarily

 

The problem was acute for businesses with uneven credit balances under CGST and SGST heads. Because the portal forced CGST credit before SGST for residual IGST payment, SGST credit often remained locked — leading to:

  • Unnecessary cash outflow from the Electronic Cash Ledger
  • Working capital blockage despite sufficient ITC being available
  • Compliance frustration and potential interest burden
  • The so-called ‘trapped credit problem’ for businesses with high SGST balances

 

2.  The New Rule — Flexible ITC Utilisation


 

From the February 2026 tax period onwards (as clarified by GSTN Update 649 dated 19 February 2026), the GST portal now enables the following flexibility in GSTR-3B (Table 6.1):

 

✅  What is Now Allowed

1.  IGST ITC must still be utilised FIRST — this statutory requirement remains unchanged.

2.  After IGST credit is fully exhausted, taxpayers can choose to use:

•  CGST ITC alone to pay remaining IGST liability, OR

•  SGST ITC alone to pay remaining IGST liability, OR

•  Any combination of CGST + SGST in any proportion.

3.  The portal will suggest a utilisation order but will no longer enforce it.

 

2.1  What Has NOT Changed

  • IGST ITC must still be fully used before CGST or SGST credits are applied
  • Cross-utilisation rules between CGST and SGST for their own respective liabilities remain restricted
  • Total tax liability does not change — only the utilisation sequence is now flexible
  • Statutory provisions of the CGST Act and GST Rules are not amended; this is a portal-level enhancement

 

3.  Advisory Timeline & Applicability


 

Advisory / Update Date Key Change
GSTN Advisory 647 January 30, 2026 Introduced structural ITC utilisation flexibility & new interest calculation mechanism
GSTN Update 649 February 19, 2026 Clarified that IGST utilisation flexibility is operational only from February 2026 period
January 2026 GSTR-3B Filed Feb 2026 ITC sequence flexibility NOT available (Advisory 647 applies to interest calc only)
February 2026 GSTR-3B Filed Mar 2026 ITC utilisation flexibility FULLY OPERATIONAL — first period to benefit

 

4.  Practical Illustration


 

Consider a taxpayer with the following ITC balances and tax liabilities for February 2026:

 

  ITC Available (₹) Tax Liability (₹)
IGST 2,00,000 3,50,000
CGST 30,000 40,000
SGST 1,00,000 40,000

 

Old System (Pre-February 2026)

Step Action Result
1 Use IGST ITC of ₹2,00,000 against IGST liability Remaining IGST liability: ₹1,50,000
2 Portal FORCES CGST ITC of ₹30,000 against IGST Remaining IGST: ₹1,20,000; CGST ITC: ₹0
3 Use SGST ITC of ₹1,00,000 against IGST Remaining IGST: ₹20,000; SGST ITC: ₹0
4 Pay remaining IGST ₹20,000 in cash + CGST ₹40,000 in cash Cash outflow: ₹60,000

 

New System (From February 2026 Onwards)

Step Action Result
1 Use IGST ITC of ₹2,00,000 against IGST liability Remaining IGST liability: ₹1,50,000
2 Taxpayer CHOOSES to use SGST ITC of ₹1,00,000 for IGST Remaining IGST: ₹50,000; SGST ITC: ₹0
3 Use CGST ITC of ₹30,000 for IGST Remaining IGST: ₹20,000; CGST ITC: ₹0
4 Pay ₹20,000 IGST + ₹40,000 CGST + ₹40,000 SGST in cash Cash outflow: ₹1,00,000 — same total
Note Alternatively — choose CGST first, preserve SGST for SGST liability Cash outflow: ₹60,000 — SAVINGS!

 

💡  Key Insight

By using CGST ITC first for the residual IGST liability (instead of SGST), and then using

the remaining SGST credit for SGST liability, the taxpayer can save ₹40,000 in cash outflow

compared to the old forced sequence. The total tax paid remains the same — only the source changes.

 

5.  Bonus Change: Interest Calculation (GSTN Advisory 647)


 

Advisory 647 also introduced an important improvement in how interest on delayed GSTR-3B payment is calculated, effective from the January 2026 tax period:

 

Aspect Old Method New Method (Jan 2026 Onwards)
Interest Base Full delayed tax amount in cash Net liability less minimum cash balance in ECL
Benefit to Taxpayer No benefit for maintaining cash balance Interest reduced if cash was available in ECL
Portal Edits Taxpayer could edit interest downward System-computed interest cannot be reduced or altered downward.
Legal Alignment Partial alignment with Rule 88B Full alignment with Rule 88B(1)

 

This means taxpayers who maintained a balance in their Electronic Cash Ledger during a delay period will now receive credit for that balance in interest computation — reducing interest exposure for disciplined taxpayers.

 

6.  Action Points for Taxpayers & Professionals


 

Who Action Required
All GST-registered businesses Review CGST and SGST ITC balances before filing GSTR-3B each month
Businesses with high SGST surplus Consider using SGST credit for IGST liability where beneficial
Businesses with high CGST surplus Consider using CGST credit for IGST liability to preserve SGST for its own liability
CA / Tax Professionals Incorporate monthly ITC optimisation planning into compliance workflow
All taxpayers Maintain adequate Electronic Cash Ledger balance to reduce interest in case of delays
Cancelled taxpayers Note: delayed last GSTR-3B filing interest now collected via GSTR-10 (Final Return)

 

7.  Important Compliance Notes


 

⚠️  Key Reminders

• IGST ITC first is non-negotiable — the portal will still enforce full exhaustion of IGST credit before allowing CGST/SGST usage.

• This is a portal-level enhancement, not a statutory amendment to the CGST Act or Rules.

• Maintain up-to-date reconciliations (GSTR-2B vs books) as ITC flexibility does not change verification requirements.

• The portal will auto-suggest a utilisation order — taxpayers may override this suggestion for optimisation.

• For January 2026 GSTR-3B (filed in February 2026), the ITC flexibility was NOT available. Only from February 2026 period.

• Consult your CA or GST advisor to determine the optimal ITC utilisation strategy for your specific credit profile.