GSTR-1 Filing: Monthly vs QRMP, Due Dates, Late Fees, Process (2026)

What is GSTR-1?

GSTR-1 is the GST return reporting all outward supplies (sales) made during the tax period. It captures:

• B2B invoices (with GSTIN of buyer)
• B2C large invoices (above ₹2.5 lakh interstate)
• B2C small (consolidated)
• Export invoices
• Credit/debit notes
• Advances received and adjusted

GSTR-1 data flows to buyers' GSTR-2A/2B for ITC claim. Late or incorrect filing affects buyers' ITC.

Monthly vs QRMP — Choose the right scheme

Two filing frequencies based on turnover:

Monthly (Regular):

• Mandatory if turnover > ₹5 crore
• Optional below threshold
• Due date: 11th of next month

QRMP (Quarterly Return Monthly Payment):

• Optional if turnover ≤ ₹5 crore
• File GSTR-1 quarterly (by 13th of next quarter month)
• Pay tax monthly via GSTR-3B (or IFF - Invoice Furnishing Facility)

When to opt QRMP: Most small B2C businesses prefer QRMP for less paperwork. B2B businesses whose customers need monthly ITC should stay on monthly filing.

Late fee structure

Late fee per Section 47:

• Other than NIL return: ₹50/day (₹25 CGST + ₹25 SGST), capped at ₹5,000
• NIL return: ₹20/day (₹10 CGST + ₹10 SGST), capped at ₹500

Additional consequences:

• Buyers cannot claim ITC until you file GSTR-1
• Continued non-filing leads to e-way bill restrictions
• GSTR-3B cannot be filed if GSTR-1 of previous month not filed

Step-by-step filing on portal

1. Login to gst.gov.in
2. Services → Returns → Returns Dashboard
3. Select Financial Year and Period (month/quarter)
4. Click 'PREPARE ONLINE' on GSTR-1 tile
5. Fill section-wise: B2B (Table 4), B2C Large (Table 5), Export (Table 6), B2C Small (Table 7), CDN (Table 9), Advances (Table 11), HSN Summary (Table 12), Doc Issue (Table 13)
6. Click 'PREVIEW' to verify
7. Submit using DSC (companies/LLPs) or EVC (others)
8. Acknowledgment Reference Number (ARN) generated

Common errors to avoid

1. Wrong GSTIN of buyer — Affects buyer's ITC. Validate GSTIN on portal before entering.
2. HSN code mismatch — Use 4-digit HSN if turnover < ₹5 cr, 6-digit if > ₹5 cr.
3. Place of supply errors — Determines whether IGST or CGST+SGST applies. Get this right.
4. Skipping NIL months — Even if no sales, file NIL return on time.
5. Amendment delays — If you missed an invoice or made an error, amend in next month's GSTR-1 (max till November 30 of next FY).