GSTR-1 explained: the statement of your outward supplies

What GSTR-1 is and who files it

GSTR-1 is filed under Section 37 of the CGST Act and Rule 59 of the CGST Rules by every normal registered person. Composition taxpayers, input service distributors, non-resident taxable persons, OIDAR suppliers and TDS or TCS registrants do not file it; they have their own returns.

A nil GSTR-1 is still required for a period with no outward supplies, unless you are in the QRMP scheme and the period is a month for which only the optional IFF applies.

What you report

• Invoice-wise B2B supplies to registered buyers, including supplies attracting reverse charge
• Large inter-state B2C invoices individually, and other B2C supplies as a state-wise and rate-wise summary
• Exports and supplies to SEZ units or developers, with or without payment of tax
• Credit notes and debit notes, and amendments to earlier periods
• Advances received and adjusted, nil-rated, exempt and non-GST supplies
• HSN-wise summary and a summary of documents issued

Prerequisites and blocks

The portal will not let you file GSTR-1 or IFF if you have not filed GSTR-3B for the previous period, if you have not replied to a DRC-01B liability mismatch intimation, or if bank account details under Rule 10A were not added after registration. If you issue e-invoices, those details auto-populate GSTR-1 and should be checked rather than re-entered.

Errors can be corrected in GSTR-1A for the same period before GSTR-3B is filed, or by amendment in a later GSTR-1. Amendments for a financial year are allowed only up to 30 November of the following year, and the portal blocks filing of returns once three years have passed from the due date.

Common mistakes

The costliest errors are wrong buyer GSTINs, B2B sales shown as B2C, wrong place of supply that splits IGST and CGST-SGST incorrectly, and missing credit notes. Each one either denies your customer credit or creates a gap between GSTR-1 and GSTR-3B that the system flags. A late GSTR-1 attracts a late fee under Section 47, capped by notified limits.

A professional can reconcile your sales register with GSTR-1 before filing and handle amendments or mismatch intimations that follow.

Get it handled for you

Want your returns filed and reconciled every month without mismatch notices? Our team handles it end to end. Call or WhatsApp +91 63677 44602, or use the form below.

This guide explains the law in general terms as of October 2026. Time limits and requirements can depend on the facts of your case and on the notice you received.