GST compliance looks straightforward on paper — file GSTR-1, file GSTR-3B, pay what is due. In practice small errors compound every month, and by the time they surface in a notice or a blocked input tax credit they have already cost real money. Here are five mistakes we see most often, and how to catch them before they become expensive.
1. Mismatched Invoices Between GSTR-1 and GSTR-3B
GSTR-1 reports outward supplies invoice by invoice; GSTR-3B summarises the tax liability for the month. When the two do not match — a common result of last-minute manual entry — the mismatch flags the GSTIN for scrutiny and can delay refunds. Reconciling the two before every filing, rather than after, is the single highest-leverage habit in GST compliance.
2. Missing Input Tax Credit Claims
Every rupee of eligible input tax credit not claimed is a rupee of cash given up. The usual cause is simple: vendor invoices that never made it into the books, or credit claimed against invoices the vendor has not yet uploaded to their own GSTR-1. A monthly GSTR-2B reconciliation catches both before the claim window closes.
3. Late or Incorrect TDS Deduction Under GST
Businesses required to deduct TDS under GST often miss the distinction between GST TDS and income tax TDS — they are separate obligations with separate returns. Deducting at the wrong rate, or filing GSTR-7 late, triggers interest that is entirely avoidable with a monthly checklist.
4. Ignoring GSTR-2B Reconciliation
GSTR-2B is an auto-generated statement of the credit actually available based on what suppliers have filed. Businesses that claim credit from their own purchase register instead of reconciling against GSTR-2B routinely overclaim, and overclaimed credit carries interest and penalty when it is caught in assessment.
5. Filing Nil Returns Incorrectly
Even a month with zero transactions requires a nil GSTR-1 and GSTR-3B filed on time. Assuming that nothing happened means nothing to file is how businesses accumulate late fees that apply per return, per day — often more than the tax that would have been due in an active month.
None of these are difficult to avoid once you know to look for them. If a notice has already been issued, that is a different conversation and worth having early — responses to departmental notices run to strict timelines.
This article explains the position in general terms and is not legal advice. Speak to an advocate about your own facts before acting on it.
