Every month, lakhs of businesses sit down to file GSTR-3B — and most of them rush it. Here is a calmer way to think about your monthly summary return.

What GSTR-3B actually is

GSTR-3B is a summary return. You declare your outward supplies, the input tax credit (ITC) you are claiming, and the net tax payable. It does not replace GSTR-1 — the two work together, and mismatches between them are one of the most common triggers for departmental notices.

The four numbers that matter

  • Outward taxable supplies — your sales, reported in Table 3.1, including zero-rated and reverse-charge transactions.
  • Eligible ITC — the credit available as per GSTR-2B, not merely what sits in your purchase register.
  • Tax paid in cash vs. credit — how you settle the liability across your electronic ledgers.
  • Interest and late fees — computed automatically when filing is delayed.

Reconcile before you file

Ten minutes of reconciliation before filing saves hours of replying to notices afterwards.

Match your purchase register with GSTR-2B every month. If a vendor has not uploaded an invoice, follow up before you claim the credit — not after the department asks about it.

Common mistakes we see

  1. Claiming ITC that does not appear in GSTR-2B.
  2. Reporting exports and zero-rated supplies in the wrong table.
  3. Forgetting reverse-charge liability on services like goods transport and legal fees.

The RKJ rhythm

We suggest a simple monthly rhythm: close your books by the 8th, reconcile by the 10th, and file by the 12th — well ahead of the due date. Predictability is the whole game with GST.