GST Invoice vs Non-GST Invoice — What is the Difference and When to Use Which

If you run a small business or work as a freelancer in India, you have probably wondered at some point — should I be sending a GST invoice or a regular invoice? What is the difference between the two? And what happens if I use the wrong one?

These are very common questions, and the answers are actually simpler than most people think.

In this post, we will break down exactly what a GST invoice is, what a non-GST invoice is, when to use each one, and what mistakes to avoid.

What is a GST Invoice?

A GST invoice is a formal billing document issued by a business that is registered under GST. It includes all the standard invoice details — your business name, customer details, product or service description, price — plus GST-specific information like your GSTIN, HSN or SAC code, and a breakup of the tax charged (CGST, SGST, or IGST).

When you issue a GST invoice, you are legally collecting tax on behalf of the government. That tax amount needs to be deposited when you file your GST returns.

A GST invoice also allows your customer — if they are a registered business — to claim that tax back as input tax credit (ITC). This is a big deal for B2B transactions.

What is a Non-GST Invoice?

A non-GST invoice — sometimes called a simple invoice or bill of supply — is a billing document that does not include any GST. There is no GSTIN on it, no tax breakup, just the basic details of the transaction.

This is what unregistered businesses use. If you are below the GST turnover threshold and have not registered, you issue non-GST invoices for all your sales.

There is also a specific document called a Bill of Supply which registered businesses use when selling GST-exempt goods or services, or when they are under the composition scheme. This is technically different from a regular non-GST invoice, but for most small businesses the practical effect is the same — no GST is charged.

The Key Differences at a Glance

GST Invoice: - Issued by GST-registered businesses only - Includes GSTIN, HSN or SAC code, tax breakup - GST is charged on top of the base price - Customer can claim input tax credit - Required for all taxable sales above the registration threshold

Non-GST Invoice: - Issued by unregistered businesses - No GSTIN, no tax lines - Only the base price is charged - No input tax credit available for the customer - Used when turnover is below the threshold or goods/services are exempt

When Should You Use a GST Invoice?

Use a GST invoice when:

You are registered under GST — Once you have a GSTIN, you are legally required to issue GST invoices for all taxable sales. There is no choice here. If you are registered and you send a plain invoice without GST, you are not compliant.

Your customer is a registered business — B2B clients almost always prefer GST invoices because they can claim the tax back as ITC. If you are registered and your customer is registered, always issue a proper GST invoice.

You are selling taxable goods or services — Most goods and services in India attract GST. Unless your product or service is specifically exempt, you need to charge GST once you are registered.

When Should You Use a Non-GST Invoice?

Use a non-GST invoice when:

You are not registered under GST — If your turnover is below ₹20 lakhs for services (₹40 lakhs for goods) and you have not registered, you cannot charge GST. Send a plain invoice with just the amount.

You are selling exempt goods or services — Some items are completely exempt from GST — things like fresh vegetables, milk, eggs, educational services, and healthcare. Even if you are registered, you issue a Bill of Supply instead of a GST invoice for these.

You are under the composition scheme — Businesses under the GST composition scheme pay a flat tax and cannot charge GST to customers. They issue a Bill of Supply instead.

A Very Common Mistake — Charging GST Without Registration

This happens more often than you would think. A new freelancer or small business owner sees GST invoices from others, assumes they need to do the same, and starts adding GST to their invoices — without actually being registered.

This is a problem. Collecting GST without a GSTIN means you are collecting money that should go to the government but you have no legal way to deposit it. If this comes to light during an audit, it can lead to penalties.

The rule is simple — you can only charge GST if you have a GSTIN. If you are not registered, do not add any tax line to your invoice.

Another Mistake — Sending Plain Invoices After Getting Registered

The opposite mistake also happens. A business gets their GSTIN and then forgets to update their invoice format. They keep sending the same plain invoices they were using before registration.

Once you are registered, every taxable sale must have a proper GST invoice. Sending a plain invoice after registration is non-compliance and can cause mismatches in your GST returns.

The moment you get your GSTIN, update your invoice template. If you are using GST Maker, just add your GSTIN to your profile settings and all your invoices from that point on will automatically be GST-compliant.

What About Invoices for Clients Outside India?

If you are a freelancer or agency providing services to foreign clients, the rules are a little different.

Services exported outside India are zero-rated under GST. This means GST rate is 0% — you do not charge any GST to your foreign client. But if you are registered, you still need to issue an export invoice that mentions your GSTIN and marks the invoice as an export of services.

This is different from a non-GST invoice. It is a GST invoice, but with 0% tax. The distinction matters for your return filing and for claiming any ITC refunds on your expenses.

How GST Maker Handles Both Types

Whether you are registered or not, GST Maker supports both workflows.

If you are a registered business, your GSTIN is saved in your profile and auto-fills on every invoice. The correct GST type — CGST/SGST or IGST — is applied automatically based on your customer's location. SAC and HSN codes are stored against each product or service so you never have to look them up again.

If you are not yet registered, you can still use GST Maker to create clean, professional invoices without any GST lines. When you eventually register and get your GSTIN, you just update your profile and the invoices automatically shift to the GST format.

No switching tools. No learning something new. The same platform handles both stages of your business.

The Bottom Line

The decision between a GST invoice and a non-GST invoice is not really a choice — it depends on whether you are registered or not, and whether your goods or services are taxable.

If you are registered — use GST invoices for all taxable sales. If you are not registered — use plain invoices with no tax. If you are registered but selling exempt goods — use a Bill of Supply.

Get this right from the beginning and you will save yourself a lot of headaches during return filing and audits.

And if you want a tool that automatically handles the right invoice format based on your registration status, head over to gstmaker.com and try it for free.