GSTR-1 Filing Guide (2025)
GSTR-1 captures invoice-wise details of outward supplies. Data from GSTR-1 feeds recipients' GSTR-2B and auto-populates GSTR-3B.
Frequency
Monthly for most; QRMP taxpayers file quarterly (with optional IFF for first two months).
Due dates
- Monthly: 11th of the next month
- QRMP: 13th after the quarter (IFF window 1st–13th of month following first two months)
Tables overview
- Invoice-wise details to registered recipients
- Include GSTIN, place of supply, tax rate, taxable value, tax amounts
- E-invoice IRN/Ack no. auto-populates where applicable
- Large invoices (≥ ₹2.5 lakh) invoice-wise for inter-state; otherwise summaries
- State-wise summaries for others
- LUT/Bond vs with IGST
- Shipping bill number & date
- Rectify earlier period invoices
- Debit/Credit notes details
Step-by-step filing
Prepare data
- Pull sales from books/ERP
- Validate GSTINs, POS, HSN, tax rates
Reconcile with e-invoices
- Ensure all IRN-generated invoices are present
- Match document numbers and dates
Upload & validate
- Use portal or offline tool to upload JSON/Excel
- Fix validation errors (HSN, UQC, GSTIN)
Submit & file
- Submit, then file with DSC/EVC
- Download ACK and maintain records
Common mistakes
- Wrong place of supply (IGST vs CGST/SGST)
- Missing reverse charge flags
- Skipping debit/credit notes
- Not reporting advances when applicable
Best practices
- Lock numbering series; avoid duplicates
- Use HSN at 4/6 digits as per turnover rules
- Reconcile GSTR-1 vs 3B monthly
- Keep digital backups of filed data
References
- GST Portal user manual (GSTR-1)
- CBIC circulars on QRMP/IFF
- E-invoice integration advisories