Avoiding GST Pitfalls After Recent Rate Restructuring: Five Critical Compliance Gaps to Fix Now
The GST rate rejig effective from 22 September 2025 has fundamentally altered how many businesses should be raising invoices, booking input tax credit (ITC), and configuring their ERP/billing systems. The earlier 12% slab has been removed, with most impacted goods and services now taxable at either 5% or 18%, and certain specified categories being brought under a 40% GST rate in place of the earlier 28% plus compensation cess model.
Many assessees have not fully aligned their internal processes to these changes, leading to misclassification of supply, incorrect invoicing, wrong ITC claims, and potential exposure to notices, interest, and penalties.
This article walks through five recurring compliance mistakes seen after the rate overhaul, explains why they are problematic, and sets out practical steps to rectify them.
Mistake 1: Continuing to Invoice at 12% After 22 September 2025
The 12% Slab Is No Longer Operational
From 22 September 2025, the 12% GST rate slab has ceased to exist. Every good or service that earlier fell in the 12% bracket has been reclassified to a new rate, broadly as follows:
- A substantial portion has migrated downwards to 5%
- The remaining portion has shifted upwards to 18%
Assessees who continue to raise invoices at 12% after this date are inherently non-compliant.
Why Using 12% Now Is Dangerous
Persisting with the 12% rate leads to one of two outcomes:
Overcharging GST
- Where the correct rate is now 5%, but the invoice shows 12%
- Consequences:
- The receiver records ITC at 12%, even though GST law allows only 5%
- This can trigger ITC mismatches and disputes during departmental scrutiny
- Pressure may arise from customers to issue credit notes or refunds
Undercharging GST
- Where the correct rate is now 18%, but the invoice shows 12%
- Consequences:
- Short payment of output tax
- Liability for differential tax plus interest, and possible penalty
- In case of audit, authorities may treat it as a case of short payment or under-reporting
In both scenarios, the assessee’s GST compliance profile is adversely impacted.
Correction Must Be at the HSN Level, Not Just a Flat Rate Change
Simply changing the “12%” field to “5%” or “18%” in your billing software is not sufficient. The law operates at the HSN/SAC classification level, and your system must reflect that granularity.
Key steps for remediation:
- Prepare a complete HSN/SAC master for all goods and services supplied.
- Refer to the actual CBIC tariff notification issued for the rate change, available at cbic.gov.in.
- Map each HSN/SAC individually to its revised GST rate (5% or 18%, or otherwise).
- Update:
- Item master in ERP
- Invoicing templates
- Price lists and catalogues
- For invoices already issued at 12% post 22 September 2025, examine the need for:
- Issuing credit/debit notes
- Making corrections through GSTR‑1A, where the amendment window is still open
Note: Always rely on the original CBIC notification, not secondary summaries or informal rate charts, for final determination of applicable rates.
Mistake 2: Treating Rate Reduction as a Trigger to Reverse ITC
Misconception: “Rate Cut Means ITC Reversal”
Some assessees have assumed that when their output GST rate falls—say, from 18% to 5%—they must reverse proportionate ITC on inputs and input services. This approach is legally incorrect in most cases.
When ITC Reversal Is Actually Required
Under the GST framework, ITC is generally reversed when:
- The outward supply becomes exempt, i.e., nil-rated (0%), or
- The inputs or input services are used for both taxable and exempt supplies, requiring proportionate reversal, or
- Specific reversal rules (e.g., under
Section 17of the CGST Act) otherwise apply.
A mere reduction in rate (for example, from 18% to 5%) does not, by itself, make the supply exempt. As long as the supply remains taxable, ITC legally availed in accordance with the law continues to be eligible.