How to Create a GST Invoice Online (Complete Guide)

The Goods and Services Tax (GST) is a comprehensive indirect tax system that has transformed how businesses across India manage taxation. Under the GST regime, every registered business must issue GST-compliant invoices for all taxable supplies of goods and services.

A GST invoice is not just a request for payment — it is a legal document that serves as proof of supply, enables the buyer to claim input tax credit, and ensures compliance with tax authorities. Creating a proper GST invoice with accurate tax calculations, correct GSTIN details, and the right HSN or SAC codes is essential for every registered taxpayer.

This guide covers everything you need to know about creating GST invoices online, including what a GST invoice is, who needs one, the mandatory fields required, step-by-step instructions using the Crafex GST invoice generator, common mistakes to avoid, and answers to frequently asked questions.

What is a GST Invoice?

A GST invoice is a tax invoice issued under the Goods and Services Tax regime. It is a document that lists the goods or services supplied, their value, and the applicable GST charged. The invoice serves as evidence of the transaction and enables the recipient to claim input tax credit on the tax paid.

GST invoices come in several types depending on the nature of the transaction.

A tax invoice is issued for taxable supplies made to a registered person. It includes all mandatory GST fields and allows the recipient to claim input tax credit.

A bill of supply is issued for exempt supplies or by composition dealers. It does not include GST charges and does not qualify for input tax credit.

A receipt voucher is issued when payment is received before the supply is made. It serves as an advance receipt and is adjusted against the final tax invoice.

A refund voucher is issued when the recipient returns goods or cancels a service, documenting the refund of tax paid.

The most common type is the tax invoice, which businesses issue for their regular taxable transactions.

Who Needs a GST Invoice?

Under the GST law, every registered taxpayer must issue a GST invoice for every taxable supply of goods or services. The requirement applies to a wide range of business entities.

Businesses. All businesses registered under GST — including private limited companies, partnerships, proprietorships, and LLPs — must issue GST invoices for their taxable supplies.

Freelancers. Freelancers providing taxable services — writers, designers, developers, consultants, and creative professionals — must issue GST invoices if they are registered under GST.

Agencies. Marketing agencies, creative studios, and digital agencies that provide taxable services must issue GST invoices to their clients.

Consultants. Management consultants, IT consultants, tax advisors, and business consultants registered under GST must issue tax invoices for their services.

Service providers. Professionals providing taxable services — lawyers, accountants, architects, engineers, doctors in certain cases — need to issue GST invoices.

Registered GST taxpayers. Any person or entity with a valid GST registration must issue GST invoices for all taxable outward supplies.

E-commerce operators. Sellers and service providers operating through e-commerce platforms must issue GST invoices for all supplies made through the platform.

Mandatory Details in a GST Invoice

A valid GST invoice must include the following mandatory details as required by the GST law.

Invoice number. A unique sequential number for each invoice, typically formatted as INV-001, INV-002, or following the financial year. Invoice numbers must be unique and cannot be repeated.

Invoice date. The date the invoice is issued. This determines the tax period and the due date for payment and filing.

Seller details. The full legal name, address, and GSTIN of the supplier. The GSTIN is a 15-character alphanumeric code that identifies the taxpayer.

Buyer details. The name, address, and GSTIN of the recipient if they are registered. If the recipient is unregistered, their name and address are sufficient.

GSTIN of both parties. The GSTIN of the supplier and, if registered, the GSTIN of the recipient. This is essential for input tax credit claims.

HSN or SAC code. The Harmonized System of Nomenclature code for goods or the Services Accounting Code for services. HSN codes are typically 4, 6, or 8 digits. SAC codes are 8 digits.

Taxable value. The value of the goods or services before tax is applied. This is the base amount on which GST is calculated.

CGST. Central GST — the portion of GST collected by the central government. CGST applies to intra-state transactions.

SGST or UTGST. State GST or Union Territory GST — the portion collected by the state or union territory government. SGST/UTGST applies to intra-state transactions.

IGST. Integrated GST — applies to inter-state transactions and imports. IGST replaces both CGST and SGST for cross-state supplies.

Total amount. The final amount payable including all taxes. This must be clearly displayed in words and figures.

Payment terms. The due date for payment, payment methods accepted, and any late payment charges.

How to Create a GST Invoice Using Crafex

Creating a GST-compliant invoice with the Crafex GST invoice generator takes four simple steps. The entire process runs in your browser, and your invoice is generated as a professional PDF ready to send.

Step 1: Enter your business details

Open the Crafex GST invoice generator. Start by entering your business information — your legal business name, address, GSTIN, phone number, and email. If you have a business logo, upload it to appear on every invoice.

The tool saves your business details for future use, so you only need to enter them once.

Step 2: Add customer details

Enter the information of the customer or client you are invoicing. Include their name or business name, billing address, and GSTIN if they are registered under GST.

If the customer is unregistered, you can leave the GSTIN field blank. The tool adjusts the invoice format accordingly.

Step 3: Add products or services with GST

List the products or services you are billing for. For each line item, enter a description, quantity, unit price, and select the appropriate HSN or SAC code if applicable.

Enter the GST rate for each item. The tool supports all standard GST rates — 0%, 5%, 12%, 18%, and 28% — and automatically calculates the taxable value, CGST, SGST (for intra-state), or IGST (for inter-state), and the total amount.

The generator handles complex scenarios like mixed GST rates on different line items, discounts, and partial exemptions.

Step 4: Generate and download the invoice

Review the invoice preview to ensure all details are correct. Verify the GSTIN, tax calculations, and total amounts.

Click generate to create your GST-compliant PDF invoice. The invoice includes all mandatory GST fields — your business details, customer information, GSTIN, HSN/SAC codes, taxable values, GST breakdown, and total amount.

Download the PDF and share it with your customer. The invoice is ready to print, email, or submit for tax records.

The entire process takes just a few minutes. No account, no installation, no accounting expertise required.

Benefits of GST Invoice Generator

Using a dedicated GST invoice generator offers significant advantages over manual invoice creation.

Automatic tax calculations. The generator automatically calculates CGST, SGST, and IGST based on the GST rates you specify. No manual math, no errors, no compliance risks.

GST-compliant format. Every invoice includes all mandatory fields required by GST law — GSTIN, HSN/SAC codes, taxable value, tax breakdown, and total. You can be confident your invoices meet legal requirements.

Professional design. GST invoices generated with Crafex feature clean, professional formatting with your business logo, consistent layout, and clear tax breakdowns.

Time savings. Creating a GST invoice manually — calculating taxes, formatting fields, and ensuring compliance — takes time. An automated generator produces a compliant invoice in minutes.

PDF export. Invoices are generated as professional PDF files that can be downloaded, printed, emailed, or shared electronically. PDF format preserves the invoice exactly as designed.

Error reduction. Manual GST invoices are prone to errors — wrong GST rates, incorrect HSN codes, miscalculated totals. An automated generator eliminates these risks.

Record keeping. Professional invoices with unique numbers and clear details make record keeping and tax filing easier at the end of each tax period.

Free and accessible. The Crafex GST invoice generator is completely free with no usage limits, subscriptions, or hidden charges.

Common GST Invoice Mistakes

Avoid these common mistakes when creating GST invoices.

Wrong GSTIN. An incorrect GSTIN on the invoice can prevent the buyer from claiming input tax credit and may result in penalties. Always verify the GSTIN before generating the invoice.

Incorrect GST percentage. Applying the wrong GST rate — using 12% instead of 18%, or mixing up CGST and IGST — results in incorrect tax calculations and compliance issues. Use the correct rate for your product or service.

Missing or duplicate invoice numbers. Every GST invoice must have a unique, sequential invoice number. Duplicate or missing numbers create problems for accounting and tax filing.

Wrong tax calculation. Manual calculation errors in taxable value, GST amount, or total can lead to disputes and compliance issues. Use an automated generator that calculates taxes correctly.

Missing HSN or SAC codes. GST invoices require the correct HSN code for goods or SAC code for services. Missing or incorrect codes can delay input tax credit claims.

Incorrect transaction type. Confusing intra-state (CGST + SGST) with inter-state (IGST) transactions leads to wrong tax calculations. Select the correct transaction type based on the buyer's state.

Not including mandatory fields. Missing fields like invoice date, due date, buyer details, or taxable value can invalidate the invoice for GST purposes. Ensure all mandatory fields are completed.

No backup copies. GST invoices are required for tax audits and compliance. Always maintain backup copies of all invoices issued.

Why Use Crafex?

Crafex provides a superior GST invoicing experience that prioritizes compliance, speed, and simplicity.

Professional templates. Your GST invoices feature clean, professional design with proper tax breakdowns, mandatory GST fields, and your business branding.

Fast. Create a complete GST-compliant invoice in minutes. Enter your details, add line items with GST rates, and generate a polished PDF — all in one seamless workflow.

Free. Creating GST invoices on Crafex costs nothing. No subscriptions, no per-invoice charges, no hidden costs.

Browser based. No software to install, no plugins, no operating system restrictions. Open the tool in any modern browser and start invoicing immediately.

PDF download. Invoices are generated as professional PDF files that can be downloaded, printed, emailed, or shared electronically.

Easy editing. Update business details, customer information, and line items easily. The tool remembers your preferences for faster invoicing.

Printable. Generated invoices are print-ready with proper formatting for physical records.

Works everywhere. Use Crafex on your desktop, laptop, tablet, or phone. Create GST invoices from the office, home, or on the go.

Comparison Table

Frequently Asked Questions

What is the difference between CGST, SGST, and IGST? CGST (Central GST) and SGST (State GST) are applied together for intra-state transactions — supplies where the buyer and seller are in the same state. IGST (Integrated GST) is applied for inter-state transactions where the buyer and seller are in different states, or for imports.

What HSN or SAC code should I use? HSN codes are used for goods and are typically 4, 6, or 8 digits. SAC codes are used for services and are 8 digits. You can find the correct code for your product or service from the GST portal or your tax advisor.

Can I create a GST invoice for an unregistered customer? Yes. You can issue a GST invoice to unregistered customers. The invoice includes your GSTIN and tax charges, but the customer's GSTIN field is not applicable.

Can I edit an invoice after generating it? You can create a new invoice with the corrected details and generate it again. Always use a new invoice number for corrected invoices and cancel the original if it has already been shared.

Do I need to register for GST to use the invoice generator? No registration is required to use the Crafex GST invoice generator. However, to legally issue GST invoices for your business, you must have a valid GST registration.

Can I download invoices as PDF? Yes. All invoices are generated as professional PDF files that can be downloaded, printed, or shared electronically.

What GST rates are supported? The generator supports all standard GST rates — 0%, 5%, 12%, 18%, and 28% — and allows custom rates for specific scenarios.

Is my invoice data secure? Yes. Your data is processed entirely in your browser and never leaves your device. The invoice generator processes everything locally with no server uploads.

Conclusion

Creating GST-compliant invoices is a legal requirement for registered taxpayers and a critical part of business operations under the GST regime. Whether you are a small business owner issuing invoices for the first time, a freelancer managing client billing, or an established company handling high volumes of transactions, a reliable GST invoice generator ensures compliance, saves time, and maintains professionalism.

Crafex makes GST invoice creation fast, accurate, and completely free. With browser-based processing that requires no installation, automatic CGST, SGST, and IGST calculations, and professional PDF output, you can create tax-compliant invoices in minutes without signing up for accounts or learning complex accounting software.

For related business workflows, explore tools for creating professional invoices, converting Word documents to PDF, reading PDFs, filling and signing documents, and protecting PDFs with passwords. Every tool follows the same privacy-first, browser-based approach.

Try the free GST invoice generator on Crafex and create your first GST-compliant invoice today.