Create GST compliant invoices with GSTIN, CGST/SGST/IGST breakdown, HSN codes, and INR formatting. No signup, no watermarks, instant PDF.
Last updated: April 6, 2026
So you're running a business in India and someone just told you that you need to issue GST invoices. Maybe your CA mentioned it. Maybe a client asked for one. Maybe you got a notice and now you're panicking a little. Whatever brought you here, let's sort this out together.
GST stands for Goods and Services Tax. India rolled it out on July 1, 2017, and it basically replaced a whole circus of older taxes. Remember VAT, service tax, excise duty, and about a dozen others? GST merged them all into one unified system. The idea was simple: one nation, one tax. In practice, well, it's a bit more involved than that. But the core concept is solid and once you understand how GST invoicing works, it becomes second nature.
A GST invoice is the official document you issue when you sell goods or services. It's not just a bill. It's a legal document that your buyer uses to claim input tax credit, that the government uses to track tax collections, and that your accountant uses to file returns. If you mess it up, your buyer can't claim their credit, and you might get a notice from the tax department. Fun times.
Not every business in India needs to register for GST or issue GST invoices. There's a threshold, and it's pretty generous for small businesses.
If you sell goods and your annual turnover is below Rs 40 lakh, you don't need GST registration. For services, the threshold is Rs 20 lakh. If you're in one of the special category states (like those in the northeast, plus Himachal Pradesh, Uttarakhand, and a few others), the limits are halved to Rs 20 lakh for goods and Rs 10 lakh for services.
But here's the catch. Even if you're below these thresholds, you might still need registration if you do interstate sales, sell through e-commerce platforms, or fall into certain other categories. And honestly? Many small businesses register voluntarily because their B2B clients insist on receiving proper GST invoices. Without a GST invoice from you, your clients can't claim input tax credit on their purchases. And nobody wants to be the supplier who costs their clients money.
Once you cross the threshold or register voluntarily, every taxable supply you make needs a proper GST invoice. No exceptions. No "I'll do it next time." Every single one.
This is where people's eyes glaze over, but stick with me because it's actually straightforward once you see the pattern.
CGST (Central GST) goes to the central government. SGST (State GST) goes to the state government. These two always show up together on intrastate transactions. So if you're in Maharashtra selling to a client who's also in Maharashtra, you'll charge, say, 9% CGST and 9% SGST for a total of 18% GST.
IGST (Integrated GST) is what you charge on interstate transactions. Selling from Maharashtra to Karnataka? That's IGST at the full rate, say 18%. The central government collects it and then settles up with the destination state later. You don't need to worry about that part.
UTGST (Union Territory GST) is the SGST equivalent for union territories like Chandigarh, Lakshadweep, Daman and Diu, and others. If you're selling within a union territory, it's CGST plus UTGST instead of CGST plus SGST.
The total tax rate is always the same. Whether you're paying 9% CGST + 9% SGST or 18% IGST, the customer pays the same amount. The split just determines which government pocket the money goes into. On your invoice, though, you need to show the correct split based on whether the transaction is intrastate or interstate. Getting this wrong is one of the most common invoicing mistakes people make.
The government doesn't leave this to your imagination. Rule 46 of the CGST Rules spells out exactly what your GST invoice must contain. Miss any of these and technically your invoice isn't valid. Here's the full list.
Supplier details. Your name (or your business name), address, and GSTIN. This goes at the top. Think of it as your tax identity card on the invoice.
A unique invoice number. This must be sequential and no longer than 16 characters. It can contain numbers, letters, special characters, and slashes. But it has to be unique for that financial year. You can't reuse numbers from last year's sequence either. So INV/2026/001 works. RANDOM123 every time does not.
Date of issue. The date you're creating the invoice. Straightforward.
Recipient details. Your customer's name, address, and GSTIN (if they're registered). If they're unregistered and the invoice value is Rs 50,000 or more, you need their name, address, and state with state code.
HSN or SAC code. More on this in a minute, but every item needs its classification code.
Description of goods or services. What exactly are you selling? Be specific. Not just "services" but "web development services" or "accounting consultation for Q3 2026."
Quantity and unit. For goods, this is obvious. 50 units, 10 kg, 200 pieces. For services, you might list hours or simply "1 service" for project based work.
Total value. The value before tax.
Taxable value. After accounting for any discounts.
Tax rate and amount. Broken down into CGST and SGST (for intrastate) or IGST (for interstate). Each line item needs its own tax calculation if different items have different rates.
Place of supply. This determines whether it's intrastate or interstate and therefore which tax split applies.
Signature. Physical or digital. Someone needs to sign off on this invoice.
That's a lot of fields, right? This is exactly why using an invoice template built for GST saves you from missing something and having to reissue.
Your GSTIN isn't a random string. It's actually a structured 15 digit identifier, and each part tells you something specific.
The first two digits are your state code. Maharashtra is 27, Delhi is 07, Karnataka is 29, and so on. These codes come from the Indian Census. Digits 3 through 12 are your PAN number. Yes, your entire PAN is embedded in your GSTIN. The 13th digit indicates the number of registrations within a state under the same PAN. Usually it's 1 unless you have multiple business verticals registered separately. The 14th digit is Z by default (reserved for future use). The 15th digit is a check digit calculated using an algorithm.
So if you see a GSTIN like 27AABCU9603R1ZM, you know it's a Maharashtra (27) entity with PAN AABCU9603R, first registration (1), default Z, and check digit M. Why does this matter for invoicing? Because you need to verify your client's GSTIN before putting it on an invoice. A wrong GSTIN means your client can't claim input tax credit, and the invoice might get flagged during return filing. Always verify on the GST portal before invoicing a new client.
HSN stands for Harmonized System of Nomenclature. It's used to classify goods. SAC stands for Services Accounting Code. It's the equivalent for services. Every item on your GST invoice needs its HSN or SAC code.
Why? Because the GST rate depends on what you're selling, and the government identifies products and services by these codes, not by whatever creative description you wrote on the invoice. Basmati rice has a different GST rate than a laptop, and the HSN code is how the system tells them apart.
How many digits do you need? It depends on your turnover. Businesses with turnover up to Rs 5 crore need 4 digit HSN codes. Above Rs 5 crore, you need 6 digit codes. For SAC codes on services, it's typically 6 digits regardless. You can look up the correct code on the CBIC website or the GST portal.
Getting the HSN/SAC code wrong can cause problems during return filing because the system cross references codes with tax rates. If the code says 5% but you charged 18%, something's going to get flagged. Take an extra minute to verify the code. Your future self will thank you. Check out our invoice examples to see how HSN codes appear on a properly formatted invoice.
This sounds like it should be obvious, and usually it is. But there are some situations that trip people up.
Intrastate means the place of supply and the location of the supplier are in the same state. You're in Mumbai, your client's delivery address is in Pune. Both Maharashtra. That's intrastate. You charge CGST + SGST.
Interstate means different states. You're in Delhi, client is in Bangalore. That's interstate. You charge IGST.
Where it gets tricky is with services. The "place of supply" for services isn't always where the client sits. For most B2B services, the place of supply is the location of the recipient (so their GSTIN state). For B2C services, it's usually the location of the supplier. There are specific rules for things like real estate services (where the property is), restaurant services (where the restaurant is), and transportation services (where the journey begins).
If you're doing B2B work and both your GSTIN and your client's GSTIN start with the same two digit state code? Intrastate. Different state codes? Interstate. That's the quick and dirty check most people use. For anything unusual, ask your CA or check the place of supply rules under Sections 10, 11, 12, and 13 of the IGST Act.
E-invoicing in India doesn't mean emailing a PDF (though you can certainly do that too). It's a specific system where your invoice data gets registered on the government's Invoice Registration Portal (IRP) and you receive an Invoice Reference Number (IRN) and a QR code that makes the invoice "official."
As of now, e-invoicing is mandatory for businesses with aggregate turnover exceeding Rs 5 crore. The threshold has been coming down over the years. It started at Rs 500 crore, then Rs 100 crore, then Rs 50 crore, then Rs 20 crore, then Rs 10 crore, and now Rs 5 crore. The trend is clear, and eventually it'll likely cover all registered businesses.
If you're above the threshold, you generate your invoice normally (with all the Rule 46 fields we talked about), then push the invoice data to the IRP. The portal validates it, generates the IRN and QR code, and sends it back. You then share the invoice with the QR code with your buyer. The whole process takes seconds if you're using accounting software that integrates with the IRP.
If you're below the threshold, you don't need e-invoicing yet. A regular GST invoice (like what you'd create with our invoice generator) is perfectly valid. Just make sure it has all the mandatory fields. When the threshold eventually includes you, your invoicing habits won't need to change much because you'll already have the right data on every invoice.
Sometimes things go wrong after you've issued an invoice. The client returns goods. You overcharged by accident. You gave an additional discount after the fact. That's where credit notes and debit notes come in.
A credit note reduces the value of the original invoice. If you sold 100 units but the client returned 10, you issue a credit note for those 10 units. This reduces the tax liability for that period and adjusts the buyer's input tax credit. Credit notes must reference the original invoice number and date, describe the reason for the adjustment, and show the tax impact.
A debit note increases the value. Maybe you undercharged, or additional charges came up that weren't on the original invoice. The debit note adds to the original transaction value and the associated tax.
Both credit notes and debit notes need to be reported in your GST returns. They're not just informal adjustments between you and your client. The government tracks them because they affect tax collections. Under Section 34 of the CGST Act, credit notes for a financial year must be issued before the earlier of two dates: the return filing date for September of the following year, or the date of filing the annual return. Miss that deadline and you can't issue the credit note for GST purposes.
Think of it this way. The original invoice is the story. Credit notes and debit notes are the corrections and additions to that story. And the tax department wants to read every chapter.
Alright, enough theory. Let's actually make a GST invoice. The whole thing takes about two minutes, and you don't need to create an account or hand over your email.
Head to the invoice creator. You'll see a clean form waiting for you.
Fill in your business details. Your business name, address, and most importantly, your GSTIN. This goes in the "from" section at the top. If you're a sole proprietor, your name works fine. If you're a company or LLP, use the registered name exactly as it appears on your GST certificate.
Add your client's information. Their business name, address, GSTIN, and state. Getting the state right is crucial because that's how you determine whether to charge CGST+SGST or IGST. If your client is unregistered, you can skip the GSTIN but include their state for place of supply purposes.
Set your invoice number and date. Use a sequential numbering system. Something like GST/2026/001 works well. The date should be the date you're actually issuing the invoice.
Add your line items. For each item, enter a clear description, the HSN or SAC code, quantity, unit price, and the applicable tax rate. The tool calculates the tax amounts automatically. If it's an intrastate sale, set up your tax as split CGST and SGST. For interstate, use the full IGST rate.
Set the currency to INR. This should be the default for domestic Indian transactions, but double check it's showing the rupee symbol.
Add payment details. Your bank account number, IFSC code, and bank name. UPI ID is also great to include since so many payments in India happen through UPI these days.
Download your PDF. Click the download button and you'll get a clean, professional GST invoice in PDF format. No watermarks, no branding from us, nothing except your invoice. Print it, email it, WhatsApp it to your client. Whatever works.
The whole thing is processed in your browser. Your data never leaves your computer. We don't store your GSTIN, your client details, or your invoice amounts on any server. It's all local, all private. Which, honestly, is how it should be when you're dealing with business financial documents.
Privacy guarantee: All invoice data stays in your browser. Your GST invoice is generated locally on your device. Nothing is uploaded to our servers. Not your GSTIN, not your client details, not the amounts. Your financial data remains entirely yours.
After seeing thousands of GST invoices (okay, maybe not thousands, but a lot), certain mistakes pop up again and again. Here are the ones that cause the most headaches.
Wrong GSTIN. Either yours or your client's. One transposed digit and the invoice becomes useless for input tax credit purposes. Always verify the GSTIN on the official portal before using it on an invoice for the first time.
Incorrect tax split. Charging IGST on an intrastate transaction or CGST+SGST on an interstate one. This happens more than you'd think, especially when businesses operate across multiple states. Check the state codes in both GSTINs before deciding the split.
Missing HSN/SAC codes. Some people leave these blank thinking they're optional. They're not. Every line item needs a classification code. The number of digits depends on your turnover bracket.
Invoice number gaps or duplicates. Your invoice numbering needs to be sequential within a financial year. Gaps raise questions during audits, and duplicates are a serious red flag. Use a system that auto increments so you don't accidentally skip or repeat numbers.
Late invoicing. Under GST, you must issue an invoice at or before the time of supply. For goods, that's typically when goods are removed or made available to the buyer. For services, it's within 30 days of completing the service. Issuing invoices months later violates the law and creates reconciliation problems. We wrote about this and other issues in our guide on common invoicing mistakes.
No place of supply. This field determines the tax split and the state that receives the SGST portion. Missing it can invalidate the entire tax calculation on the invoice.
India has multiple GST rate slabs, and knowing which one applies to your goods or services saves you from charging the wrong amount.
The 18% slab is where most B2B service invoices land. If you're a freelance developer, consultant, designer, or agency, chances are you're at 18%. Always confirm the exact rate for your specific HSN/SAC code though, because there are exceptions and special provisions within each slab. Understanding your tax obligations on invoices is crucial whether you're dealing with GST or VAT in other countries.
You've made it through the GST invoicing crash course. You know about the four types of GST, the mandatory fields under Rule 46, how GSTIN numbers work, when e-invoicing kicks in, and how credit notes function. That's genuinely more than most business owners know, and it puts you in a strong position to invoice correctly from day one.
The only thing left is to actually create your invoice. Open the free invoice creator, plug in your details, add your line items with the right HSN codes and tax rates, and download your PDF. It takes a couple of minutes. It costs nothing. There are no watermarks, no account requirements, and your data never leaves your browser. Just a clean, GST compliant invoice ready to send to your client.
No account. No setup. GST compliant invoice in under 2 minutes.
Add your business name, address, GSTIN, and your client's details.
List goods or services with HSN/SAC codes, quantities, and rates.
Choose CGST+SGST for intrastate or IGST for interstate. Tax calculates automatically.
Get a clean, GST compliant PDF invoice instantly. No watermarks.
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