How to Create a GST Invoice for Free in 2026 (Complete Step-by-Step Guide)

Every registered GST business in India is legally required to issue a GST-compliant tax invoice for every sale. Getting even one mandatory field wrong can cause your buyer to lose their Input Tax Credit (ITC) — leading to disputes and lost business.

This guide walks you through exactly what a valid GST invoice looks like, what fields are mandatory, and how to create one for free in under 2 minutes.

What is a GST Invoice?

A GST Invoice (also called a Tax Invoice) is a document issued by a GST-registered seller to a buyer. It is the official record of a supply of goods or services and is required for:

• The buyer to claim Input Tax Credit (ITC)
• The seller to file GSTR-1 (outward supplies)
• Audit and compliance records

Mandatory Fields in a GST Invoice (Rule 46)

Under Rule 46 of the CGST Rules, 2017, a tax invoice must contain the following fields:

#	Field	Details
1	Name of Supplier Required	Your registered business name
2	Supplier GSTIN Required	Your 15-digit GSTIN number
3	Supplier Address Required	Your registered business address
4	Invoice Number Required	Consecutive, unique per financial year
5	Invoice Date Required	Date of supply or issue
6	Buyer Name & Address Required	Recipient's name and address
7	Buyer GSTIN	Required if buyer is GST registered (for B2B)
8	HSN / SAC Code Required	Harmonized code for goods (HSN) or services (SAC)
9	Description of Goods/Services Required	Clear description of what was supplied
10	Quantity & Unit	Required for goods (Nos, Kg, Ltrs, etc.)
11	Taxable Value Required	Value before GST
12	GST Rate & Amount Required	CGST+SGST or IGST separately stated
13	Total Invoice Value Required	Total including all taxes
14	Place of Supply Required	State where supply is made (determines intra/inter state)
15	Signature / Digital Sign	Physical or digital signature of authorized person

Step-by-Step: How to Create a GST Invoice for Free

GST Invoice Number Format — Best Practices

B2B vs B2C Invoice Rules

Invoice Type	Buyer	GSTIN Required?	ITC Eligible?
B2B Tax Invoice	GST-registered business	✅ Yes	✅ Yes (buyer can claim)
B2C Invoice	Unregistered individual	❌ No	❌ No
Export Invoice	Foreign buyer	❌ No (write "URP")	Refund applicable

Frequently Asked Questions

Can I create a GST invoice without GSTIN?

No. To issue a proper Tax Invoice, you must be GST registered and have a GSTIN. If you are below the threshold (₹40 lakh for goods, ₹20 lakh for services) and unregistered, you issue a regular bill/receipt — not a GST invoice.

What is the time limit to issue a GST invoice?

For goods: On or before the date of delivery. For services: Within 30 days of the date of supply (45 days for banking/insurance companies).

Can I issue a handwritten GST invoice?

Yes, but it must contain all mandatory fields. Digital or printed invoices are strongly recommended for cleanliness and ITC matching in GSTR-2B.

Do I need to print invoices in duplicate?

For goods: Original for buyer, duplicate for transporter, triplicate for seller. For services: Original for buyer, duplicate for seller. Digital invoices are sufficient for services.

Is an e-invoice mandatory for me?

As of 2026, e-invoicing (IRP Portal) is mandatory for businesses with annual turnover above ₹5 crore. Below this threshold, regular tax invoices are acceptable.