GST Notices Are Rarely Random
Most GST notices to early-stage Indian startups trace back to one of a handful of avoidable mistakes — not aggressive tax planning gone wrong, just process gaps that compound over a few filing cycles.
Here are the five most common, and exactly how to avoid each one.
Table of Contents
- Mistake 1: Mismatched GSTR-1 and GSTR-3B Figures
- Mistake 2: Claiming ITC Without Matching GSTR-2B
- Mistake 3: Missing E-Invoicing Thresholds
- Mistake 4: Incorrect Place of Supply on Services
- Mistake 5: Late or Inconsistent Filing
- FAQ
- Conclusion
Mistake 1: Mismatched GSTR-1 and GSTR-3B Figures
When outward supply reported in GSTR-1 doesn't match the summary filed in GSTR-3B, it's one of the most common automated flags the GST system generates.
This usually happens when:
- Invoices are amended after GSTR-1 is filed, but the correction isn't carried through to GSTR-3B
- A return is filed in a hurry with estimated numbers and never reconciled
- Sales from a particular state are omitted from one return but not the other
Fix: Reconcile GSTR-1 vs. GSTR-3B before filing 3B every month. The GSTN portal itself provides a reconciliation tool — use it.
Mistake 2: Claiming ITC Without Matching GSTR-2B
Input Tax Credit claimed that doesn't appear in your GSTR-2B (because a vendor hasn't filed their return) is a frequent trigger for demand notices.
Many startups run a month-end ITC claim based on purchase invoices in hand. If a vendor's GSTR-1 is late or incorrect, that ITC won't appear in your 2B — and claiming it exposes you to a demand plus 18% interest.
Fix: Reconcile ITC claims against GSTR-2B every month, not just at year-end. Chase vendors whose ITC doesn't appear consistently — or switch to vendors with a strong filing track record.
Mistake 3: Missing E-Invoicing Thresholds
As turnover thresholds for mandatory e-invoicing have been progressively lowered, many startups cross the threshold without realizing it and keep issuing regular invoices.
As of 2024-25, e-invoicing is mandatory for businesses with aggregate annual turnover exceeding ₹5 crore. This threshold was ₹500 crore in 2020 — it has been stepped down significantly and may be lowered further.
Fix: Check your applicable threshold at the start of each financial year, and set a calendar reminder to re-check at each revision. Once you cross the threshold, all B2B invoices must be generated through the IRP (Invoice Registration Portal).
Mistake 4: Incorrect Place of Supply on Services
For startups selling SaaS or services across states, getting the place of supply wrong is a common and costly error.
If the place of supply is wrong:
- You may charge CGST/SGST instead of IGST (or vice versa)
- The customer can't claim the ITC you've charged
- You face potential reverse charge liability
Common scenarios where this goes wrong:
- SaaS sold to a customer in a different state from your registered office
- Consulting services where the service location and customer location differ
- Export of services (must qualify under zero-rated supply)
Fix: Implement a place of supply determination step in your billing process. For SaaS sold to GST-registered businesses across India, the place of supply is the customer's state — charge IGST regardless of where you're located.
Mistake 5: Late or Inconsistent Filing
A pattern of late filings — even by a few days — increases the likelihood of scrutiny under the GST risk-based assessment system. It also incurs interest at 18% p.a. from the due date and a late fee of ₹50 per day (₹20 for nil returns).
More importantly, late filings break your customers' ITC claims — which damages your vendor relationships.
Fix: Build a compliance calendar with reminders set 5 days before each due date. GSTR-3B is due by the 20th of the following month for most taxpayers; GSTR-1 is due by the 11th. Make these non-negotiable.
Conclusion
None of these issues require a large finance team to avoid. They require a monthly reconciliation habit: GSTR-1 vs. 3B, ITC vs. 2B, and a filing calendar that doesn't slip.
Most startups that receive a GST notice weren't doing anything wrong on purpose — they just didn't have anyone checking these four things every month. If compliance keeps slipping through the cracks, this is exactly the kind of ongoing work we take off founders' plates at FinanceBridge.