GST Invoice Formats Guide for India 2025 — Tax Invoice, Bill of Supply, Credit Note and More

GST requires specific invoice formats depending on the nature of the transaction. Using the wrong format — or missing mandatory fields — can invalidate your recipient's ITC claim and expose you to penalties. This guide covers every GST invoice format, what it must contain, and when to use it.

1. Tax Invoice (Most Common)

When to Use

• •Any taxable supply of goods or services by a GST-registered supplier
• •B2B transactions where the recipient is GST-registered and needs ITC

Mandatory Fields

Every GST Tax Invoice must contain:

1.Supplier details: Name, address, GSTIN, state name and code

2."Tax Invoice" as the heading (mandatory exact wording)

3.Consecutive serial number: Unique for each financial year. Can be alphanumeric. Must be unique across branches if you have multiple GSTINs

4.Date of issue

5.Recipient details: Name, address, GSTIN (for B2B). For unregistered B2C buyers, name and address if the invoice value exceeds ₹50,000

6.Place of supply: State where the supply is made (determines CGST+SGST vs IGST)

7.HSN/SAC code: For goods, 4-digit or 8-digit HSN based on turnover. For services, SAC code

8.Description of goods/services

9.Quantity and unit of measurement

10.Total taxable value

11.GST rate and amount (separately for CGST, SGST, or IGST)

12.Total invoice value (in words and figures)

13.Signature or digital signature of the supplier or authorised representative

Time Limit for Issuing

• •Goods: Before or at the time of removal/delivery
• •Services: Within 30 days of supply (45 days for banking companies)

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2. Bill of Supply

When to Use

• •Registered suppliers under the Composition Scheme (cannot charge GST)
• •Supplies of exempt goods or services (no GST applicable)

Key Difference from Tax Invoice

A Bill of Supply does NOT show GST amounts. The heading says "Bill of Supply" — not "Tax Invoice." No GSTIN is shown for composition dealers on the invoice header.

Mandatory Fields

Same as Tax Invoice except: no GST rate or amount; heading "Bill of Supply"; composition dealer must mention "Composition Taxable Person, not eligible to collect tax on supplies."

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3. Credit Note

When to Issue

• •Goods returned by the buyer
• •Post-supply discount that was not already reflected in the original invoice
• •Deficiency in supply or quality
• •Any other situation where the taxable value or tax charged is reduced

What a Credit Note Does

• •Reduces your GST liability for the tax period in which you issue it
• •The recipient's ITC is correspondingly reversed

Mandatory Fields

Same as Tax Invoice, plus:

• •Heading: "Credit Note"
• •Reference to the original Tax Invoice number and date

Time Limit

Must be issued by the earlier of:

• •30th November following the end of the financial year in which the original supply was made, OR
• •Date of filing annual return (GSTR-9)

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4. Debit Note

When to Issue

• •Taxable value or GST charged was less than the actual amount
• •Additional supply or charges after the original invoice
• •Any situation where the supplier needs to collect more than the original invoice

Effect on GST

Increases the supplier's GST liability. The recipient can claim the additional ITC.

Mandatory Fields

Same as Tax Invoice, plus:

• •Heading: "Debit Note"
• •Reference to the original Tax Invoice

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5. Delivery Challan

When to Use (Rule 55, CGST Rules)

• •Goods sent for job work (without immediate tax invoice)
• •Liquid gas where quantity is determined only at delivery point
• •Goods sent on approval basis (sale subject to approval)
• •Branch transfers where invoice will be raised separately
• •Goods sent for exhibition or trade fair

What It Is NOT

A Delivery Challan is not a tax invoice. It does not create a GST liability. It is a transport document for goods movement without a corresponding tax invoice.

Mandatory Fields

• •"Delivery Challan" as heading
• •Date and delivery challan number
• •Supplier name, address, GSTIN
• •Consignee (recipient) name, address, GSTIN if registered
• •HSN code, description, quantity, taxable value
• •Signature of supplier

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6. E-Invoice (IRN)

Who Must Generate E-Invoices

Businesses with aggregate turnover exceeding ₹5 crore in any preceding financial year. This threshold has been progressively lowered and may be reduced further.

What Is an E-Invoice?

An e-invoice is a Tax Invoice that has been registered on the Invoice Registration Portal (IRP) and assigned an Invoice Reference Number (IRN) and a digitally signed QR code.

Important: The physical format of the invoice does not change. You still print and send a normal invoice. The e-invoice requirement is that before issuing the invoice, you register it on the IRP and get the IRN.

Process

1.Generate the invoice in your billing software

2.System uploads invoice details to IRP via API

3.IRP validates the invoice, generates IRN and QR code

4.IRN and QR code are embedded in the invoice

5.Invoice is issued to buyer with IRN and QR code

A Tax Invoice issued without IRN (when mandatory) is considered not a valid invoice for ITC purposes.

What DaaSu Does

DaaSu's GST E-Invoicing module handles IRN generation via IRP API integration automatically — when you create an invoice in DaaSu for an applicable transaction, the IRN is generated and the QR code embedded without manual steps.

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Common GST Invoice Mistakes to Avoid

1.Missing HSN/SAC code — Required based on turnover slab. 4-digit, 6-digit, or 8-digit depending on turnover

2.Wrong place of supply — Determines inter-state (IGST) vs intra-state (CGST+SGST). Common error for service businesses

3.Incorrect GSTIN on invoice — Always validate recipient's GSTIN on the GST portal before issuing

4.Missing "Tax Invoice" heading — The exact words are required; "Invoice" alone is insufficient

5.No serial number continuity — Invoice numbers must be consecutive within a financial year; gaps create scrutiny

6.Issuing Tax Invoice for exempt supplies — Should be Bill of Supply instead

7.Missing IRN for applicable businesses — Invoices without mandatory IRN are invalid for ITC

DaaSu's GST billing module handles all invoice formats with built-in compliance checks — ensuring mandatory fields are never missed. Start a free trial and generate your first compliant invoice in minutes.