GST Return Filing: Complete Checklist for Businesses

The GST Compliance Calendar: What Files When

India's Goods and Services Tax (GST) regime requires registered businesses to file multiple returns each month, quarter, or year depending on their turnover, registration type, and scheme opted. Missing deadlines triggers interest at 18% per annum on the tax liability and late fees ranging from ₹50 to ₹200 per day (capped at ₹10,000 per return). For businesses under the Quarterly Return Monthly Payment (QRMP) scheme, late fees are calculated differently.

Understanding which return applies to your business is the first step. The two most important returns for most regular taxpayers are GSTR-1 (outward supplies) and GSTR-3B (summary return with tax payment). Annual reconciliation happens through GSTR-9 and, for larger taxpayers, the certified reconciliation statement GSTR-9C.

GSTR-1: Reporting Your Sales

GSTR-1 is a statement of all outward supplies (sales) made during the tax period. It must be filed by the 11th of the following month for monthly filers and by the 13th of the month following the quarter for QRMP taxpayers. Every invoice you issue : B2B, B2C (large), exports, credit notes, debit notes : must be reported here.

The detail required in GSTR-1 is granular: GSTIN of the buyer for B2B invoices, HSN/SAC codes, invoice number and date, taxable value, and tax amount split by IGST/CGST/SGST. For B2C small transactions (below ₹2.5 lakh for inter-state), you can aggregate by state rather than report individual invoices.

• B2B invoices: report individually with buyer's GSTIN.
• B2C large (inter-state > ₹2.5 lakh): report individually, buyer's GSTIN not required.
• B2C small: aggregate by state code.
• Exports: report under Table 6A with shipping bill details.
• Credit notes and debit notes: link to the original invoice in Table 9B/9C.
• HSN summary (Table 12): mandatory if annual turnover > ₹5 crore; 6-digit HSN. Optional (4-digit) for ₹1.5–₹5 crore; 2-digit for below ₹1.5 crore.

GSTR-3B: The Summary Return and Tax Payment

GSTR-3B is a monthly self-declared summary return where you report net tax liability and pay it. For monthly filers, it is due by the 20th of the following month. QRMP taxpayers file quarterly GSTR-3B but pay tax monthly via the PMT-06 challan (by the 25th of each of the first two months of the quarter).

The single most important column in GSTR-3B is Table 4 : Input Tax Credit (ITC). You can only claim ITC on purchases where your supplier has filed GSTR-1 and the invoices appear in your GSTR-2B. Claiming ITC on invoices not in GSTR-2B is a compliance risk that can result in demand notices from the tax authority.

Maximising Input Tax Credit (ITC): The Golden Rules

ITC is the lifeline of GST compliance : it is the mechanism by which tax paid on inputs is offset against tax collected on outputs, preventing cascading taxation. However, ITC has extensive conditions, and improperly claimed ITC attracts 24% interest plus penalty equal to the ITC amount.

• Only claim ITC on goods and services used for business purposes : personal use is blocked.
• Motor vehicles (not used for transportation of goods/passengers) attract blocked ITC.
• Food, beverages, outdoor catering, beauty treatment, health services, and club memberships are blocked credits.
• Works contract services for immovable property construction: ITC blocked.
• Ensure the supplier has paid their GST : your ITC is conditional on this.
• Match every purchase invoice against GSTR-2B before filing GSTR-3B.
• ITC must be claimed within the earlier of: the due date of GSTR-3B for September of the next financial year, or the date of filing the annual return.
• Provisional ITC (up to 5% of eligible ITC in GSTR-2B) is no longer available : claim only what is in GSTR-2B.

GSTR-2B Reconciliation: Your Monthly Ritual

GSTR-2B is an auto-drafted, static statement generated on the 14th of each month, reflecting all invoices your suppliers have filed against your GSTIN in their GSTR-1. It is the authoritative source for ITC claims under Rule 36(4). Make GSTR-2B reconciliation a monthly non-negotiable before filing GSTR-3B.

Common reconciliation mismatches: supplier filed with wrong GSTIN, invoice date in one month but supplier filed in a later month, supplier has not filed GSTR-1 at all (chase them before the 11th), or the invoice value/tax amount differs. Each mismatch needs a resolution path : either a corrected invoice, a credit note, or communication with the supplier.

Annual Returns: GSTR-9 and GSTR-9C

GSTR-9 is the annual return consolidating all monthly/quarterly returns filed during the financial year. It is due by December 31st of the following financial year (extended most years). For FY 2023-24, the deadline is December 31, 2024. Taxpayers with aggregate turnover up to ₹2 crore are exempt from GSTR-9 but can still file voluntarily.

GSTR-9C is a reconciliation statement comparing the annual GSTR-9 figures with the audited financial statements. It must be certified by a Chartered Accountant or a Cost Accountant and is mandatory for taxpayers with aggregate turnover exceeding ₹5 crore.

Pre-Filing Checklist

• Download GSTR-2B for the period and reconcile all purchase invoices.
• Match your sales register with GSTR-1 filed data : no missing or duplicate invoices.
• Verify HSN/SAC codes on all invoices issued.
• Check for any pending credit notes or debit notes from the previous period.
• Confirm all export invoices carry the correct shipping bill numbers.
• Verify the tax rate applied to each supply : rate errors compound over time.
• Ensure no ITC is claimed on blocked credits (motors, food, personal expenses).
• Cross-verify tax payable with electronic cash and credit ledger balances on the GST portal.
• Keep all physical invoices and supporting documents for six years from the due date of the annual return.

Penalties for Non-Compliance

• Late fee for GSTR-1/GSTR-3B: ₹50/day (₹25 CGST + ₹25 SGST) for returns with tax liability; ₹20/day for nil returns.
• Maximum late fee per return: ₹10,000 (periodically waived/reduced by GST Council amnesty schemes).
• Interest on delayed payment: 18% per annum on the unpaid tax amount.
• Wrongful ITC claim or excess refund: penalty of 100% of the tax amount.
• Suppression of taxable supplies: penalty of 100% of tax evaded.
• Repeated defaults can lead to cancellation of GST registration.