GSTR-3B Filing: Common Mistakes to Avoid
Learn about the most common errors in GSTR-3B filing and how to prevent them. From ITC mismatches to late fees and place-of-supply errors, this guide helps Indian businesses file GSTR-3B correctly and avoid notices.
GSTR-3B is a monthly summary return that every GST-registered person must file. It declares your outward supplies (sales), input tax credit (ITC) claimed, reverse charge liability, and net tax payable. The return is due by the 20th of the following month (e.g., January GSTR-3B is due by 20 February).
Because GSTR-3B is a self-declaration, errors are common — and they can lead to notices, interest, and late fees. Knowing the typical mistakes helps you file correctly the first time.
GSTR-1 contains invoice-wise details of your outward supplies. GSTR-3B Table 3.1 summarizes the same in aggregate. The GST portal automatically compares both and flags discrepancies.
Common causes: Entering different taxable values or tax amounts, including invoices in one return but not the other, or using wrong tax rates. Even small rounding differences can trigger mismatches.
How to avoid: Reconcile GSTR-1 and GSTR-3B before filing. Ensure the total taxable value and tax in GSTR-3B Table 3.1 matches the sum of all invoices in GSTR-1. Use our GSTR-3B calculator to verify figures.
Input tax credit (ITC) is claimed in Table 4 of GSTR-3B. Under Rule 36(4), you cannot claim ITC beyond a specified percentage (e.g., 110%) of the amount reflected in GSTR-2B. Claiming excess ITC leads to notices and reversal.
- Claiming ITC on invoices not yet uploaded by suppliers
- Claiming ITC on blocked items (e.g., personal use, motor vehicles)
- Not reconciling purchase register with GSTR-2B
How to avoid: Reconcile your books with GSTR-2B before filing. Only claim ITC that appears in GSTR-2B (or within the notified limit). Keep supplier invoices and ensure they have filed GSTR-1.
For intra-state supplies (same state), you pay CGST + SGST. For inter-state supplies (different states), you pay IGST. Reporting the wrong place of supply leads to incorrect tax columns and potential notices.
Common errors: Treating inter-state sales as intra-state (or vice versa), wrong state codes, or mixing up B2B and B2C supplies in the wrong tables.
How to avoid: Verify the buyer's state and GSTIN. Use our place of supply calculator for complex cases. Ensure GSTR-1 place of supply matches GSTR-3B.
GSTR-3B is due by the 20th of the following month. Late filing attracts:
- Late fee: ₹50 per day (₹20 for nil returns) for CGST and SGST each
- Interest: 18% per annum on the tax amount
Many taxpayers forget to file a nil return when there is no business activity. A nil return is still mandatory — not filing attracts late fees.
How to avoid: Use our GST due date calendar to track deadlines. File nil returns on time. Estimate penalties with our GST late fee calculator.
When you receive certain goods or services from unregistered suppliers, you must pay GST under Reverse Charge. This includes services like legal, accounting, and specified goods. RCM tax must be reported in Table 3.1(d) and paid in cash. ITC on RCM can be claimed in Table 4(A)(2).
Common mistake: Forgetting to add RCM liability or claiming ITC on RCM without actually paying the tax in the same return.
How to avoid: Identify all RCM transactions. Use our RCM finder to check applicability. Report RCM in Table 3.1(d) and pay before claiming ITC.
Exempt, nil-rated, and non-GST supplies should be reported in Table 3.1(b) (outward exempt) or the appropriate row. Putting them in taxable supply rows inflates your tax liability and creates mismatches.
Similarly, composition scheme supplies and exports have specific tables. Using the wrong table leads to incorrect declarations.
- Reconcile before filing: Match GSTR-1 with GSTR-3B. Ensure outward supply totals and tax amounts align.
- Reconcile ITC with GSTR-2B: Only claim ITC within the Rule 36(4) limit. Verify supplier invoices and their GSTR-1 filing.
- Verify place of supply: Use the correct state for each supply. IGST for inter-state, CGST+SGST for intra-state.
- File on time: Mark the 20th in your calendar. File nil returns even when there is no activity.
- Report RCM correctly: Identify RCM transactions, pay tax in Table 3.1(d), and claim ITC only after payment.
- Use the right tables: Exempt, nil-rated, and non-GST supplies go in the appropriate rows, not in taxable supply rows.
Frequently Asked Questions
- What is GSTR-3B?
- GSTR-3B is a monthly self-declaration return that summarizes your outward supplies (sales), input tax credit (ITC) claimed, and net GST payable. It is due by the 20th of the following month for most taxpayers.
- What happens if I file GSTR-3B late?
- Late filing attracts a late fee of ₹50 per day (₹20 for nil returns) for CGST and SGST each, plus 18% interest on the tax amount. Use our GST late fee calculator to estimate penalties.
- Why is there a mismatch between GSTR-1 and GSTR-3B?
- GSTR-1 contains invoice-wise details of outward supplies, while GSTR-3B is a summary. The GST portal compares both and flags discrepancies. Ensure the taxable value and tax amounts in GSTR-3B match the totals from GSTR-1.
- Can I claim ITC not reflected in GSTR-2B?
- Rule 36(4) limits ITC to 110% (or lower as notified) of the amount appearing in GSTR-2B. Claiming excess ITC can lead to notices and reversal. Reconcile your books with GSTR-2B before filing.
- Do I need to file GSTR-3B if I have no sales?
- Yes. Even with no business activity, you must file a nil return. Not filing attracts late fees. Use our GST due date calendar to track deadlines.
- What is reverse charge in GSTR-3B?
- Reverse Charge Mechanism (RCM) applies when you receive certain goods or services from unregistered suppliers. You must pay GST on your own and report it in Table 3.1(d) of GSTR-3B. ITC on RCM can be claimed in Table 4(A)(2).
Ready to file GSTR-3B correctly?
Use our free tools to calculate GSTR-3B liability, check due dates, and estimate late fees. Sign up for Invoism for GST-compliant invoicing and simplified compliance.