A GST Tax Invoice is a legally prescribed document under the CGST Rules, 2017 — it must contain specific mandatory fields or it is not a valid tax document for Input Tax Credit claims. Many small business owners generate invoices using Word or Excel templates that are missing required fields — HSN/SAC codes, GSTIN of both parties, proper CGST/SGST/IGST split, and the place of supply. This causes their clients to be denied Input Tax Credit during audits, leading to disputes. The Utility Spark GST Invoice Formatter ensures every mandatory field under Rule 46 of the CGST Rules is present: supplier and recipient GSTIN, HSN/SAC codes, taxable value, CGST/SGST (intra-state) or IGST (inter-state) correctly split, and the total invoice value in words. For B2B invoices above ₹5 crore, the IRN (Invoice Reference Number) field is also included.
lightbulb When to use this tool
- check_circle Generating a GST-compliant tax invoice for a B2B client who will claim Input Tax Credit.
- check_circle Creating invoices with correct CGST/SGST vs IGST determination based on place of supply.
- check_circle Formatting invoices with HSN/SAC codes that are required at different turnover thresholds.
- check_circle Ensuring invoices meet all mandatory fields under CGST Rule 46 before sending to clients.
Why use our tool?
CGST/SGST vs IGST Auto-Determination
The GST split depends on whether the supply is intra-state (supplier and recipient in same state → CGST + SGST, each at 50% of total GST rate) or inter-state (different states → IGST at full rate). The formatter auto-selects the correct split based on the supplier and recipient state inputs.
HSN/SAC Code Field with Validation
HSN codes (for goods) and SAC codes (for services) are mandatory per CGST Rules — 4-digit HSN for turnover ₹1.5–5 crore, 6-digit for ₹5+ crore. The form includes the HSN/SAC field prominently.
Amount in Words Auto-Generated
The total invoice amount in words (as required by GST rules) is auto-generated from the numeric total — e.g. 'Rupees Forty-Two Thousand Five Hundred Only'.
How it works
Enter supplier details: legal name, GSTIN, address, state.
Enter recipient details: GSTIN (for B2B), address, state.
Add line items: description, HSN/SAC code, quantity, unit, rate, GST rate.
The CGST/SGST or IGST split auto-calculates based on states.
Add bank details for payment.
Click 'Generate Invoice' and download as PDF.
Examples
science B2B Service Invoice (Intra-State)
Supplier: Mumbai agency (GST: 27XXXXX) | Client: Mumbai company (GST: 27YYYYY)
Same state (Maharashtra) → CGST + SGST split
Service: Web development | SAC: 998313 | ₹50,000
CGST 9%: ₹4,500 | SGST 9%: ₹4,500
Total: ₹59,000