GST Invoice Guide for Small Business in India (Fields, Rules, Examples)
Every field a GST-compliant invoice needs — CGST/SGST/IGST, HSN, invoice number, place of supply — with examples for Indian small businesses.
A GST invoice is more than a bill — it is the legal document that carries input tax credit. Getting the fields wrong causes buyer disputes, ITC rejection and CA rework at month-end.
Mandatory fields on a GST invoice
- Supplier name, address, GSTIN.
- Buyer name, address, GSTIN (if registered).
- Sequential invoice number (unique per financial year).
- Date of issue and place of supply.
- HSN or SAC code per line item.
- Quantity, unit price, discount, taxable value.
- CGST + SGST (intra-state) or IGST (inter-state) rate & amount.
- Total value in figures and words.
- Signature or authorised digital signature.
Intra-state vs inter-state
When supplier and buyer are in the same state, split tax as CGST + SGST. Different states → single IGST. AIFlowBiz derives this automatically from the buyer's state.
How AIFlowBiz handles it
Enter buyer details once. Add line items with HSN. Tax splits, totals and PDF are generated on the fly. Share on WhatsApp with a Razorpay link in one tap.
Frequently asked
Do I need a GSTIN to raise a GST invoice?
Yes — you must be GST-registered to charge GST. Non-registered businesses can raise a regular bill of supply.
How long must I keep invoices?
At least 72 months (6 years) from the due date of the annual return for that financial year.
Run this in AIFlowBiz
Connect your store, generate GST-ready invoices, automate inventory and ecommerce orders, and compare plans.