How to Make a GST Invoice Online Free in India

GST invoicing does not have to be complicated

If you just got GST-registered, or if you have been registered for a while but still feel unsure whether your invoices are fully compliant, you are not alone.

Most small business owners and freelancers in India learn invoicing by copying someone else's format, hoping it is correct. Sometimes it is. Sometimes it is not, and the problem only surfaces during a GST audit or when a client's accounts team rejects the invoice because a mandatory field is missing.

Getting your GST invoice format right from the start saves you from rejected Input Tax Credit claims, compliance notices, and awkward conversations with clients.

This guide covers exactly what a GST invoice must include, how the tax calculation works, and how to generate a correct one online for free in under two minutes.

Who needs to issue a GST invoice?

If you are registered under GST, you are legally required to issue a GST-compliant tax invoice for every taxable supply of goods or services. This applies whether you are:

• A freelancer or consultant providing services
• A small business selling products
• An agency billing a client
• A shop owner making B2B sales
• A service provider billing a corporate client

If your annual turnover is below the GST threshold (Rs. 20 lakhs for most states, Rs. 10 lakhs for certain North-Eastern states), you are not required to register. In that case, you issue a regular invoice without GST. But once you cross the threshold or register voluntarily, GST invoicing becomes mandatory for every taxable transaction.

What a GST invoice must include: the 16 mandatory fields

Under Rule 46 of the CGST Rules, a tax invoice issued by a GST-registered business must contain these fields. Missing even one of them makes the invoice non-compliant:

Supplier details:

• Name of the supplier
• Address of the supplier
• GSTIN of the supplier

Invoice details:

• A consecutive serial number (unique within a financial year, maximum 16 characters)
• Date of issue

Recipient details:

• Name of the recipient
• Address of the recipient
• GSTIN of the recipient (for B2B invoices where the recipient is registered)
• Place of supply (the state where the service is consumed or goods are delivered)

Item details:

• Description of goods or services
• HSN code (for goods) or SAC code (for services)
• Quantity and unit of measure (for goods)
• Total value of supply

Tax details:

• Taxable value after discounts
• Rate of tax (CGST, SGST, or IGST as applicable)
• Amount of tax charged (separately for CGST, SGST, or IGST)

Other fields:

• Signature or digital signature of the supplier or their authorised representative

That is the complete mandatory list under GST law. A well-designed invoice generator handles all of these automatically once you enter your basic details.

CGST, SGST, or IGST: which tax do you charge?

This is where most people get confused. The answer depends on one thing: whether your client is in the same state as you or a different state.

Intra-state supply (same state): If you and your client are in the same state, you charge CGST + SGST. Both are at half the applicable rate. For the 18% slab (which covers most services), that is CGST at 9% and SGST at 9%.

Inter-state supply (different state): If you and your client are in different states, you charge IGST instead. For the 18% slab, IGST is 18% as a single tax.

Export of services: If you are providing services to a client outside India, your supply is zero-rated. You do not charge any GST. However, you must still issue an invoice and mention that it is an export invoice for zero-rated supply.

Example: A graphic designer in Mumbai invoices a client in Pune (same state, Maharashtra): Charges CGST 9% + SGST 9% = 18% total.

The same designer invoices a client in Delhi (different state): Charges IGST 18% instead.

The Invoice Generator on EasyQuickTool calculates the tax amount automatically once you enter the rate. You just need to know which type applies to your invoice.

What is an SAC code and do you need it?

SAC stands for Service Accounting Code. It is a 6-digit code assigned by the GST Council to classify different types of services for tax purposes.

If you provide services (as most freelancers and consultants do), you must include the correct SAC code on your GST invoice.

Here are the most common SAC codes for Indian freelancers:

If you are unsure about your SAC code, the GST Council's official SAC code list is searchable online. Using the wrong SAC code is a compliance issue, so it is worth getting right.

How to make a GST invoice online free: step by step

The Invoice Generator on EasyQuickTool creates GST-compliant invoices with all the required fields in under two minutes.

1. Open the tool in your browser - no account, no software to install

2. Enter your business details:

   • Your name or business name
   • Your address
   • Your GSTIN
   • Your contact details

3. Enter your client's details:

   • Client name and company name
   • Client address
   • Client GSTIN (for B2B invoices)
   • Place of supply

4. Set your invoice number and date:

   • Use a sequential number: INV/2026-27/001
   • Set the invoice date
   • Set the due date (Net 15 or Net 30 is standard)

5. Add your line items:

   • Description of the service
   • SAC code
   • Quantity (if applicable)
   • Rate and amount

6. Add GST:

   • Enter CGST + SGST rates for same-state clients
   • Enter IGST rate for clients in a different state
   • The tool calculates the tax amount and total automatically

7. Add any discounts if applicable

8. Add your bank details and UPI ID for easy payment

9. Download the PDF - your GST invoice is ready to send

GST invoice number format: the rules you must follow

Your GST invoice number must be:

• Unique within a financial year - no two invoices can have the same number
• Sequential - no gaps allowed. If you issue INV-001 and INV-002, your next invoice must be INV-003, not INV-005
• Maximum 16 characters - including letters, numbers, hyphens, and forward slashes
• Not reusable - a cancelled invoice number cannot be reused

A simple and widely used format for Indian businesses:

INV/2026-27/001 for the first invoice of financial year 2026-27 INV/2026-27/002 for the second, and so on.

Reset the counter at the start of each financial year (April 1). Your first invoice in April 2027 would be INV/2027-28/001.

Gaps in your invoice sequence are a red flag during GST audits and can trigger questions from the tax department. Keep your numbering clean and consistent from the start.

When must you issue a GST invoice?

GST law sets time limits for issuing invoices:

For services: The invoice must be issued within 30 days of the date of supply (when the service was completed or delivered).

For banking and financial services: Within 45 days.

For goods: At or before the time of delivery.

Issuing invoices late is a compliance violation. In practice, issue your invoice as soon as the work is done or the goods are delivered. Do not let it sit for weeks.

B2B vs B2C GST invoices: what changes?

The basic format stays the same, but there are some differences:

B2B invoice (business to registered business):

• Must include the recipient's GSTIN
• Must include place of supply
• The recipient uses this invoice to claim Input Tax Credit
• Getting the details right matters more because errors affect the client's ITC claim

B2C invoice (business to individual or unregistered business):

• Recipient's GSTIN is not required (they are not registered)
• For invoices above Rs. 2.5 lakh in inter-state B2C supply, additional details are required
• The recipient cannot claim ITC regardless of invoice format

For most freelancers billing corporate clients, you are issuing B2B invoices. For freelancers billing individuals directly, B2C rules apply.

Can you issue a GST invoice in any language?

GST law does not prescribe a specific language. Invoices can be in English or any Indian language. In practice, English is the most widely used and accepted across states, especially for B2B transactions.

If you are billing a local client who prefers invoices in a regional language, that is permitted as long as all the mandatory fields are present and accurate.

Common GST invoice mistakes and how to avoid them

Wrong tax type. Charging CGST + SGST on an inter-state invoice, or IGST on an intra-state one, is a compliance error. The client cannot claim the correct ITC and you may face a notice. Always check the state of supply before choosing the tax type.

Missing GSTIN. For B2B invoices, your client's GSTIN is mandatory. Without it, they cannot claim Input Tax Credit on your invoice. Always ask for their GSTIN before raising the invoice.

Wrong SAC code. Using a generic or incorrect SAC code is a compliance issue. Check the official list for your specific service.

Gaps in invoice numbers. Sequential numbering without gaps is a GST requirement. Do not skip numbers, and do not reuse cancelled invoice numbers.

Issuing invoice too late. Waiting weeks after completing a project to raise the invoice can put you outside the 30-day window. Issue invoices promptly.

Not mentioning place of supply. This is mandatory and determines which tax (CGST+SGST or IGST) applies. Do not leave it out.

Do you need accounting software for GST invoicing?

Not necessarily. Accounting software like Tally, Zoho Books, or QuickBooks handles GST invoicing, return filing, and reconciliation in one place. If you handle a high volume of invoices every month or have complex GST filing needs, dedicated software makes sense.

But if you are a freelancer or small business owner raising a handful of invoices each month, a free online invoice generator covers your invoicing needs completely. You create the invoice, download the PDF, send it to the client, and keep a copy for your records. Simple, fast, and free.

For GST return filing (GSTR-1, GSTR-3B), you will need to file separately on the GST portal regardless of what tool you use for invoicing.

Keep copies of every invoice

GST law requires you to maintain invoice records for at least six years. Keep a copy of every invoice you issue, either as a PDF on your computer or in cloud storage.

A simple folder system works well: one folder per financial year, invoices named by number. INV-2026-27-001.pdf, INV-2026-27-002.pdf, and so on. When tax filing time comes, every invoice is exactly where you need it.

Your GST invoice is two minutes away

You now know the mandatory fields, the correct tax type for your situation, the SAC code for your service, and the numbering rules. Everything you need to issue a fully compliant GST invoice is in one place.

The invoice generator handles the formatting and calculations. You fill in the details and download the PDF.

Create your GST invoice now, free