GST Bill Generator — Free GST Invoice Maker India (2025)

7 min read · GST Invoicing · Invoice Practice Lab

A GST invoice is a mandatory document for any registered business in India selling goods or services above ₹200 to another GST-registered buyer. Understanding the correct format of a GST invoice is essential for students, accountants, business owners, and anyone involved in financial operations. This free GST bill generator lets you create a sample GST invoice with all mandatory fields — correct format, proper tax breakup, and no login required.

Educational Disclaimer: Invoices generated on Invoice Practice Lab are sample documents for educational and practice purposes only. They are not valid GST invoices for filing returns, claiming input tax credit, or any official tax purpose. For real GST invoicing, use GST-compliant accounting software.

What is a GST Invoice?

A GST invoice (also called a tax invoice under GST) is a document that a registered supplier issues when selling taxable goods or services. It is the primary document for:

Claiming Input Tax Credit (ITC) by the buyer
Reporting outward supplies in GSTR-1 by the seller
Proof of transaction for audit and compliance purposes
Legal documentation of B2B and B2C commercial transactions

Without a proper GST invoice, the buyer cannot claim ITC, making it one of the most important documents in India's tax ecosystem.

Mandatory Fields in a GST Invoice (As Per GST Rules)

Rule 46 of the CGST Rules, 2017 specifies the mandatory fields that every tax invoice must contain. Here is a complete list:

Field	Details
Supplier's Name	Legal name of the registered business issuing the invoice.
Supplier's GSTIN	15-digit GST Identification Number of the supplier. Format: State Code (2) + PAN (10) + Entity Code (1) + Check Digit (1) + Z (1).
Supplier's Address	Principal place of business as registered with GST authorities.
Invoice Number	Unique sequential number. Must be consecutive within the financial year. Cannot repeat.
Invoice Date	Date of issue. For services, must be within 30 days of supply. For banking/insurance, within 45 days.
Recipient's Name and Address	Buyer's legal name and address. For B2B, the buyer's GSTIN must also be mentioned.
Recipient's GSTIN	Required for B2B invoices. For B2C invoices above ₹2.5 lakh, recipient's state must be mentioned.
HSN / SAC Code	Harmonized System of Nomenclature code for goods, or Service Accounting Code for services. Determines the applicable GST rate.
Description of Goods / Services	Clear description of what is being sold or the nature of the service provided.
Quantity and Unit	For goods: quantity supplied and the unit of measure (e.g., KG, PCS, LTR).
Taxable Value	The value on which GST is calculated — typically the transaction price minus any applicable discounts.
GST Rate	The applicable GST rate: 5%, 12%, 18%, or 28% depending on the HSN/SAC code.
CGST Amount	Central GST — applicable on intra-state (within same state) transactions. Half the total GST rate.
SGST / UTGST Amount	State GST / Union Territory GST — applies alongside CGST for intra-state transactions.
IGST Amount	Integrated GST — applies on inter-state (between different states) transactions. Equal to the full GST rate.
Total Invoice Value	Taxable Value + Total GST (CGST+SGST or IGST) + any other charges.
Place of Supply	The state/UT where the supply is deemed to occur. Determines whether CGST+SGST or IGST applies.
Whether GST is Payable on Reverse Charge	Must state Yes/No. If Yes, the recipient pays GST instead of the supplier.
Supplier's Signature	Physical or digital signature of the authorized signatory.

GST Invoice Rules India 2025 — Key Compliance Points

E-invoicing is mandatory for businesses with annual turnover above ₹5 crore (as of 2025). The invoice must be reported to the IRP (Invoice Registration Portal) and an IRN + QR code obtained before sharing with the buyer.
Time limit for issuing invoice: For goods — at the time of supply. For services — within 30 days of supply. For continuous supply of services — within 30 days of the due date of each payment.
Three copies for goods: Original (buyer), Duplicate (transporter), Triplicate (supplier's record).
Invoice series reset: The invoice numbering series resets each financial year (April 1). You must notify GST authorities of any changes to the series format.
Credit notes and debit notes must reference the original invoice number and must be issued within the annual return filing deadline.

      CGST+SGST vs IGST: If your supplier and buyer are in the same state, use CGST + SGST (split equally). If they are in different states, use IGST only. The total tax amount is the same — only the routing changes. Getting this wrong is one of the most common GST filing errors.
    

When Do You Need a GST Invoice?

GST invoices are required in several everyday business situations:

B2B Purchases — Input Tax Credit

When your business buys goods or services from another GST-registered vendor, you need a valid GST invoice to claim the Input Tax Credit (ITC) on that purchase. Without an invoice meeting all mandatory fields, ITC cannot be claimed and the GST paid becomes a sunk cost for your business.

Expense Reimbursement

Employees claiming business expenses (travel, accommodation, software subscriptions) need to provide GST invoices for their company's accounts team to claim ITC. A simple receipt or payment confirmation is not sufficient — the document must show the supplier's GSTIN, HSN/SAC code, and proper tax breakup.

Government Contracts and Tenders

Any business supplying to government departments must issue GST-compliant invoices. Government entities have strict compliance requirements and may reject non-compliant bills, delaying payment.

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Frequently Asked Questions

What is the difference between a GST invoice and a bill of supply?

A GST tax invoice is issued when selling taxable goods or services and shows GST charged to the buyer. A Bill of Supply is issued by composition scheme taxpayers or for exempt goods/services — it does not charge GST. If you are under the composition scheme, you cannot issue a tax invoice and must use a Bill of Supply instead.

Can I issue a GST invoice without being GST registered?

No. Only GST-registered businesses with a valid GSTIN can issue GST tax invoices. If you are unregistered, you should issue a regular invoice without any GST charges. Issuing a fake GST invoice with a non-existent GSTIN is a criminal offence under the GST Act.

What is HSN code and how do I find it for my product?

HSN (Harmonized System of Nomenclature) is an internationally standardized system for classifying goods. Every product has an HSN code that determines its GST rate. You can find the correct HSN code for your goods on the GST portal at gst.gov.in under the "Search HSN Code" tool. Services use SAC (Service Accounting Code) instead.

Is e-invoicing mandatory for small businesses?

As of FY 2025, e-invoicing (generating an IRN from the IRP portal) is mandatory for businesses with aggregate annual turnover above ₹5 crore. Businesses below this threshold are not mandatorily required to e-invoice, but it is recommended for streamlined GSTR-1 auto-population. The threshold has been progressively reduced over the years and may decrease further.

For more on understanding GST receipts in practice, read our blog article on how GST applies to Uber receipts — a practical example of GST in everyday transactions.