GSTR-1 vs GSTR-3B: what each return needs from your billing

Every month (or quarter), a GST-registered business in India answers two questions for the government: what did you sell, invoice by invoice? and how much tax do you owe after credits? GSTR-1 answers the first. GSTR-3B answers the second.

If your billing is clean, both returns are a matter of minutes. If it isn’t, they become a monthly fire drill. Here is what each return needs, and how to set up your billing so the data is ready when you are.

GSTR-1: the detail of your sales

GSTR-1 is a statement of outward supplies. It lists your sales so that your business customers can see them and claim input tax credit. It includes:

• B2B invoices with the customer’s GSTIN, invoice number, date, value, place of supply and tax.
• B2C sales, summarised (large inter-state B2C invoices are reported individually).
• Credit and debit notes issued in the period.
• Exports, nil-rated and exempt supplies, and an HSN-wise summary.

Because your customers’ input credit depends on it, mistakes in GSTR-1 cause phone calls you don’t want.

GSTR-3B: the summary and the payment

GSTR-3B is a summary return. It totals your outward supplies and tax liability, subtracts the input tax credit you are entitled to on purchases, and you pay the balance. Where GSTR-1 is invoice by invoice, GSTR-3B is totals.

Your input credit is checked against what your suppliers reported in their own GSTR-1, so keeping purchase records accurate matters just as much as sales.

How the two connect

The sales totals in GSTR-3B should agree with the detail in GSTR-1 for the same period. When they don’t, it is usually because:

• an invoice was added or edited after one return was filed;
• a credit note appears in one return but not the other;
• an inter-state sale was charged CGST + SGST instead of IGST (or the reverse);
• the place of supply on the invoice is wrong.

Set up your billing so returns write themselves

1. Capture the customer’s GSTIN on every B2B sale, and their state.
2. Put HSN / SAC codes on products once, so every invoice and the HSN summary are right.
3. Let the system choose IGST or CGST + SGST from the place of supply, rather than cashiers deciding.
4. Use credit notes, never edits, to correct a filed invoice.
5. Record purchases with the supplier’s GSTIN so you can match input credit.

Due dates and thresholds

Monthly filers generally file GSTR-1 by the 11th and GSTR-3B by the 20th of the following month; quarterly (QRMP) filers have different dates. Dates and thresholds change, so always check the current calendar on the GST portal.

How ZaleBee helps

In ZaleBee, the invoices you already create carry the GSTIN, HSN and correct tax split, so GSTR-1 and GSTR-3B ready data, and e-invoice and e-way bill JSON, come straight from your sales and purchases. You or your accountant then file on the portal.