A GST invoice is more than a bill — its format is defined by law, and a missing field can make it non-compliant. Whether you write invoices by hand or use an app, this is the checklist every Indian business should follow.
Mandatory fields in a GST invoice
- Supplier’s name, address and GSTIN
- A consecutive serial number unique for the financial year
- Date of issue
- Recipient’s name, address and GSTIN (for registered buyers)
- HSN code for goods or SAC code for services
- Description, quantity and unit of each item
- Taxable value and any discount
- GST rate and amount — CGST + SGST for intra-state, IGST for inter-state
- Whether tax is payable on reverse charge
- Signature or digital signature of the supplier
Common mistakes that break compliance
- Non-sequential or duplicate invoice numbers
- Charging CGST/SGST on an inter-state sale (it should be IGST), or vice-versa
- Missing or wrong HSN/SAC codes
- Forgetting the recipient GSTIN on B2B invoices
Let the app handle the format
The simplest way to never get the format wrong is to use software that enforces it. GSTify fills your GSTIN, numbers invoices sequentially, applies the correct CGST/SGST or IGST based on the place of supply, and keeps HSN/SAC with each product — so every PDF you generate is compliant by default.
Stop worrying about format. Download GSTify and generate correct GST invoices automatically.