Learn the 10 most frequent GST return blunders—wrong GSTIN, excess ITC, missed RCM, and more—and discover quick, practical fixes to keep filings clean
1. Entering the Wrong GSTIN
A single-digit slip can derail your entire GST return. When the buyer’s GSTIN is wrong, their input-tax credit (ITC) vanishes, and your sales total won’t match the portal.
Fix it fast
- Verify GSTINs on the portal before uploading.
- If you’ve already filed, amend the invoice in the next GSTR-1 under “Amendments.”
- Re-issue a corrected tax invoice if needed.
2. Misclassifying Interstate vs Intrastate Supply in GST Return
Choosing CGST + SGST instead of IGST (or the other way around) skews tax liability and can trigger a notice during GST return scrutiny.
Your action plan
- Check “place of supply” rules in the IGST Act for every new customer.
- Discovered late? Pay the right tax via Form DRC-03 and adjust future returns.
3. Forgetting to Upload Sales Invoices in GSTR-1
If the invoice never lands in GSTR-1, it never lands in the buyer’s GSTR-2B. Result: ITC blocked, angry customer, messy GST return reconciliation.
Quick cure
- Reconcile your sales ledger with the GSTR-1 summary by the 10th.
- Missed one? Report it next month under “B2B Amendments” and notify the buyer.
4. Claiming ITC Missing from GSTR-2B
Since 1 Jan 2022, provisional ITC is gone—only ITC shown in GSTR-2B can be claimed in your GST return.
Fix
- Match purchase ledgers with GSTR-2B monthly.
- Push vendors to file on time; save proof of reminders.
- Reverse ineligible credit in your next GSTR-3B and reclaim once visible.
5. Missing the GST Return Due Date
Late fees pile up at ₹50 per day for most taxpayers (₹20 if NIL). Interest at 18 % joins the party.
| Return | Normal due date | Late fee/day* |
|---|---|---|
| GSTR-1 | 11 th | ₹50 |
| GSTR-3B | 20 th / 22 nd / 24 th | ₹50 or ₹20 |
*Interest extra on unpaid tax.
Prevent it
- Create calendar alerts three days before each GST return deadline.
- File NIL returns by SMS if no transactions occurred.
6. Uploading B2B Invoices as B2C
A wrong flag during bulk upload means the buyer never gets ITC and your GST return needs an amendment.
Solution
- Amend under “B2C(O)→B2B” in the next GSTR-1.
- Validate GSTIN length (15 chars) for every B2B invoice before uploading.
7. Ignoring Reverse-Charge Mechanism (RCM)
| Supply type | Who pays under RCM? |
|---|---|
| Goods Transport Agency freight | Recipient |
| Import of services | Importer |
| Security services (non-company vendor) | Recipient |
Steps
- Maintain an RCM checklist per month.
- Pay RCM via cash ledger, then claim ITC in the very same GST return cycle.
8. Claiming ITC on Blocked Credits
Personal motor cars, club memberships, real-estate builds—Section 17(5) says “no credit.” Claiming them invites reversal plus 18 % interest.
How to stay safe
- Tag suspicious ledger heads as “blocked” in your accounting software.
- Reverse voluntarily in GSTR-3B before an audit does it for you.
9. Skipping NIL GST Return
Even if you recorded no sales or purchases, GSM law still requires a NIL GST return. Skip two cycles and the portal may suspend your account and block e-way bills.
Fast track
- File NIL GSTR-3B and GSTR-1 via the SMS shortcut for ultimate speed.
10. Neglecting GST Return -9/9C (Annual Return)
Turnover over ₹2 crore? GSTR-9 is compulsory. Beyond ₹5 crore? Add GSTR-9C with CA certification.
Checklist
- Download the auto-drafted GSTR-9 in April, not December.
- Reconcile turnover, tax paid, and ITC with books early.
- Keep digital work-papers ready for the CA’s signature (if 9C applies).
One-Sheet Action Plan for Every GST Return Cycle
- GST Master Sheet with customer GSTINs and place-of-supply codes.
- Reconcile sales/purchases vs GSTR-1 & 2B by the 10 th of each month.
- Colour-code ITC—Green (in 2B), Amber (pending), Red (blocked).
- RCM tracker for freight, legal, import, security services.
- SMS NIL filing on dormant months.
- Annual return prep by October, no last-minute chaos.
Final Thoughts
A clean GST return isn’t magic—it’s habit: reconcile, review, remind. Nail that rhythm and you’ll avoid penalties, free your cash flow, and sleep easier at night.
If your backlog feels overwhelming, Indefine has rescued hundreds of businesses from GST tangles. Drop us a line; we’ll have your next GST return filed accurately and on time—every time.
