Common GST filing mistakes — and how to avoid them
Written by Tax Paramarsh editorial teamReviewed by Tax Paramarsh GST deskLast updated 3 October 2026Applies to: GST rules in force on 3 October 2026
Most GST notices start with small, repeatable mistakes. Here are the ones we see most, and how to stop them happening again.
In GSTR-1
- B2B sales reported as B2C, or with a wrong GSTIN.
- Credit notes not issued for returns and discounts.
- Wrong rates or HSN codes after the September 2025 rate changes.
In GSTR-3B
- Claiming credit not yet in GSTR-2B.
- Claiming blocked credits — food, personal use, certain vehicles.
- Missing reverse-charge tax on services like legal fees or freight.
In the process
- Filing late, so late fees and interest pile up.
- Not paying suppliers within 180 days — credit must then be reversed.
- Leaving returns unfiled for months — they can’t be filed after three years.
How to avoid them
Close sales data by the 5th, reconcile purchases with GSTR-2B every month, check rates whenever the law changes, and approve returns before filing — not after.
Key takeaways
- Get sales data right — GSTR-3B now follows GSTR-1.
- Claim only eligible credit that is in 2B.
- A fixed monthly routine prevents most notices.
Common questions
Can I revise a GST return?
There is no revision as such; corrections go through GSTR-1A before 3B or amendments in later months.
Will a small mistake lead to a notice?
Often a mismatch triggers an ASMT-10 scrutiny notice. A clear reconciliation usually closes it.
Related
General information, reviewed on 3 October 2026 — not advice for your specific case. GST rules, forms and due dates change; talk to us before acting.