Overview

GSTR-1 is a mandatory monthly or quarterly GST return that contains details of all outward supplies (sales) made by a registered GST taxpayer during a specific tax period. It is governed under the Central Goods and Services Tax (CGST) Act, 2017 and must be filed on the GST portal within prescribed due dates. GSTR-1 captures invoice-level data of B2B sales, B2C sales, exports, credit/debit notes, advances received, and amendments to previous returns. The data filed in GSTR-1 directly flows to the recipient’s GSTR-2A/2B, making accuracy critical to avoid mismatches, ITC disputes, and notices. Timely and correct GSTR-1 filing ensures GST compliance, smooth input tax credit flow to customers, avoidance of late fees, interest, and departmental scrutiny.