GST · Glossary
GSTR-1
Monthly or quarterly return of outward supplies (sales) filed by every registered taxpayer.
Updated 2026-10-08Source: Income-tax Act · CGST Act · CBDT/CBIC
What it means
GSTR-1, prescribed under Section 37 of the CGST Act, 2017 read with Rule 59 of the CGST Rules, is the return where you report all your outward supplies (invoices issued) to the GST system. Each invoice is broken into B2B (registered customers), B2CS (small unregistered customers), B2CL (large unregistered customers), exports, and credit/debit notes. The filing frequency is monthly by default; taxpayers under the QRMP scheme (turnover < Rs. 5 crore) file quarterly with monthly summary payments.
The data you file here feeds your customers' GSTR-2A and GSTR-2B — i.e., it determines whether they can claim Input Tax Credit on the GST you charged them. Late or incorrect GSTR-1 filings directly hurt your customers' ITC eligibility and damage commercial relationships.
A worked example
For Priya, a Mumbai-based designer who raised 6 B2B invoices to KA + MH clients in April 2026, GSTR-1 for that month lists each invoice in Table 4A with the client GSTIN, place of supply, and IGST/CGST/SGST split — due by 11 May 2026 (monthly filer).
File on time even if you have zero sales — nil GSTR-1 is mandatory while your GSTIN is active. Late filing blocks subsequent GSTR-3B and attracts a late fee of Rs. 50/day (Rs. 20/day for nil), CGST and SGST together, capped by last year's turnover: Rs. 500 for a nil return, Rs. 2,000 up to Rs. 1.5 crore, Rs. 5,000 up to Rs. 5 crore and Rs. 10,000 above that.
Run it on your own numbersFree GST Invoice Generator — no signup.Going deeper: GSTR-1 Filing for Freelancers: Complete Step-by-Step Guide (2026-27) — 10 min read.
Look up the details
- GST rates & SAC codes — the rate and SAC for any service.
- All 28 terms — the full glossary, by category.
Sources
Income-tax entries cite the Income-tax Act 1961, which governs FY 2025–26 (the return filed in 2026); from tax year 2026–27 the Income-tax Act 2025 applies, with new section numbers shown where we give them. GST law is unchanged. General information, not tax advice; verify with your CA before you file.
Related terms
Compliance without the vocabulary
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HourSlip works out the GST on each invoice, logs every TDS deduction and estimates your advance-tax instalments — you check the numbers, and the glossary stays optional.
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