GST Invoice Format: The Complete Compliance Checklist for 2026

Key Takeaways

A GST tax invoice in 2026 must include sixteen particulars under Rule 46 of the CGST Rules, 2017, covering supplier and recipient details, HSN/SAC, description, quantity and unit, taxable and total values, tax rates and amounts, place of supply, delivery address, reverse charge indicator, and signature.
Missing or incorrect recipient GSTIN blocks Input Tax Credit (ITC) for buyers; for unregistered buyers with taxable value of ₹50,000 or more, capture name, address, delivery address, State name, and State code on the invoice.
HSN digit count depends on turnover: 6 digits for businesses above ₹5 crore on all invoices, 4 digits for businesses up to ₹5 crore on B2B invoices; wrong digit counts frequently trigger scrutiny.
Export and Reverse Charge invoices require mandatory legends on the face of the document; omitting them renders the invoice incomplete even if other fields are correct.
Invoice serial numbers must be consecutive, unique per financial year, and within sixteen characters using only alphabets, numerals, hyphens, and slashes; non-compliance invites reconciliation queries and penalties.

A single missing field on a GST tax invoice can block your buyer's ITC claim — and the dispute lands back on your desk at month-end. Under Rule 46 of the CGST Rules, 2017, every registered supplier must include sixteen mandatory particulars on a tax invoice. Get one wrong, and your customer loses ITC; get the serial number format wrong, and you risk a penalty of up to ₹25,000 per contravention under Section 125 of the CGST Act.

A GST tax invoice must contain all particulars prescribed under Rule 46 of the CGST Rules, 2017, from the supplier's GSTIN to the place of supply for inter-State transactions. The format applies to all registered suppliers of goods and services, with specific variations for exports, Reverse Charge Mechanism (RCM) supplies, composition taxpayers, and large B2C businesses. The governing authority is the Central Board of Indirect Taxes and Customs (CBIC).

GST Invoice Format: The Short Answer

A GST tax invoice is a document issued by a registered supplier that creates the legal basis for the buyer's ITC claim and the supplier's output tax liability.

Supplier name, address, GSTIN — Rule 46(a) — ABC Pvt Ltd, Mumbai — 27AAAAA0000A1Z5
Invoice serial number — Rule 46(b) — INV/2025-26/001 (max 16 chars)
Date of issue — Rule 46(c) — 12 August 2026
Recipient name, address, GSTIN/UIN — Rule 46(d) — XYZ Ltd — 29BBBBB1111B1Z3
HSN/SAC code — Rule 46(g) — 8471 (computers); 998314 (IT services)
Taxable value and tax rate — Rule 46(i),(j) — ₹1,00,000 @ 18% IGST
Tax amount (CGST + SGST or IGST) — Rule 46(k) — ₹18,000 IGST
Place of supply with State name — Rule 46(l) — Karnataka (29)
Reverse charge indicator — Rule 46(n) — Yes / No
Supplier signature — Rule 46(o) — Authorised signatory

The rule most commonly broken: Showing the State name without the two-digit State code, or showing the code without the name. Rule 46 requires both for inter-State supplies.

What Must Be On A GST Tax Invoice To Be Compliant In 2026

Every field on a GST tax invoice either protects the buyer's ITC or establishes the supplier's tax liability — there is no cosmetic detail. Rule 46 of the CGST Rules, 2017 lists sixteen particulars; missing even one makes the document technically deficient.

Supplier And Recipient Identification Fields

The invoice must carry the supplier's legal name, registered address, and GSTIN at the top. For the recipient, the requirement splits by registration status.

Registered recipient: Name, address, and GSTIN or UIN. The GSTIN determines which State receives the SGST credit and whether the supply is treated as inter-State or intra-State. A wrong GSTIN — even a one-digit typo — means the buyer's ITC is linked to a non-existent supplier in GSTR-2B.

Unregistered recipient (taxable value ₹50,000 or more): Name, address of recipient, delivery address, State name, and State code are all mandatory (Rule 46(d), CGST Rules, 2017). For values below ₹50,000 to unregistered buyers, these fields are optional — but capturing them anyway costs nothing and simplifies any future query.

Transaction Detail Fields

HSN/SAC + description: The HSN code classifies the goods; SAC classifies the service. The description must be specific enough to identify the supply — “goods” or “services rendered” will not survive an audit.

Quantity and unit (goods only): The Unit Quantity Code (UQC) must match the standard codes prescribed by CBIC — for example, “NOS” for numbers, “KGS” for kilograms. A mismatch between the UQC on your invoice and the UQC in your customer's purchase order is a common e-way bill flag.

Taxable value: This is the value after applying any discounts or abatements. The total value, pre-discount, must also appear separately. Both fields are required — do not show only the post-discount figure (Rule 46(h)(i), CGST Rules, 2017).

Tax rate and amount: Show the rate and rupee amount for each component separately — CGST and SGST for intra-State, IGST for inter-State, UTGST for Union Territory supplies, and Cess where applicable.

Place Of Supply And Delivery Address

For inter-State supplies, the place of supply (PoS) along with the State name and two-digit State code is mandatory on the face of the invoice (Rule 46(l), CGST Rules, 2017). If the delivery address differs from the PoS — for example, goods supplied to a Delhi-registered entity but delivered to a warehouse in Pune — both addresses must appear.

Rounding rule: Tax amounts are rounded to the nearest rupee at the invoice level. If the tax fraction is 50 paise or more, round up; below 50 paise, drop it (Rule 50, CGST Rules, 2017). Do not round at line level — aggregate first, then round the total.

Reverse Charge And Signature

If the supply attracts RCM — where the recipient pays the tax instead of the supplier — the invoice must state “Tax payable on reverse charge basis” prominently. This is not a footer note; it must be visible on the face of the document.

The invoice must be signed or digitally signed by the supplier or an authorised representative. For e-invoices, electronic invoices with an Invoice Reference Number, or IRN, the CBIC has clarified that a physical signature is not required on the printed copy — the IRN and QR code serve as authentication.

AiA's Tally sync and AP & bills automation validate customer and vendor masters — name, GSTIN, and address — before posting back to Tally. Mismatches are flagged before the invoice is finalised, so a wrong GSTIN or stale address does not survive to the printed document.

Frequently Asked Questions About Mandatory GST Invoice Fields

Is a digital signature mandatory on a GST tax invoice in 2026?

A digital or physical signature of the supplier or an authorised representative is required under Rule 46(o) of the CGST Rules, 2017. For e-invoices generated through the IRP and carrying a valid IRN, a separate wet or digital signature is not required on the printed copy — the QR code and IRN act as authentication. For invoices not covered by e-invoicing, a signature remains mandatory.

What happens if the recipient's GSTIN is wrong on the invoice?

A wrong GSTIN means the invoice does not appear in the buyer's GSTR-2B — the auto-populated ITC statement. The buyer cannot claim ITC until the supplier issues a credit note against the incorrect invoice and reissues a corrected invoice with the right GSTIN. The correction should happen before the supplier files GSTR-1 for the relevant period to avoid a mismatch flag.

How To Design A GST Invoice In Excel Or Word Without Errors

A well-structured GST invoice format in Excel or Word does two things: it mirrors the sixteen mandatory fields from Rule 46, and it uses cell-level controls to stop incorrect entries before they reach the customer. The gst invoice format in excel and gst invoice format in word approaches differ slightly in flexibility, but the underlying field structure is identical.

Column Layout For A GST Invoice Format In Excel

Structure the invoice in three blocks:

Header block (rows 1–10, typically):

Supplier name, address, GSTIN, State code
Invoice number, text field, max 16 characters — use data validation to enforce length
Invoice date
Recipient name, address, GSTIN/UIN
Delivery address, if different
Place of supply with State code

Line-item block (one row per item):

A — Sr. No. — Auto-fill
B — Description — Free text
C — HSN/SAC — Dropdown from master list
D — Qty — Numeric
E — UQC — Dropdown (NOS, KGS, MTR, etc.)
F — Unit Rate (₹) — Numeric
G — Taxable Value (₹) — =D×F minus discount
H — GST Rate (%) — Dropdown (5, 12, 18, 28)
I — CGST (₹) — =G×H/2, intra-State only
J — SGST (₹) — =G×H/2, intra-State only
K — IGST (₹) — =G×H, inter-State only

Footer block:

Total taxable value, sum of column G
Total tax, CGST + SGST or IGST — sum before rounding
Rounded tax total, =ROUND(sum,0) — round at invoice level, not per line
Grand total
“Tax payable on reverse charge: Yes/No”, dropdown
Signature line

Three Excel controls that prevent the most common errors:

Data validation on the GSTIN cell, 15-character alphanumeric pattern check.
Conditional formatting to flag when IGST and CGST/SGST are both non-zero on the same invoice — a structural impossibility.
A formula that checks invoice serial number length: =IF(LEN(B3)>16,"EXCEEDS LIMIT","OK").

GST Invoice Format In Word: When To Use It

A GST invoice format in Word works for low-volume, service-heavy businesses where each invoice is manually drafted. Use a table-like layout with locked header and footer cells and editable line-item rows. Word's "Restrict Editing" feature can lock all non-input fields.

The key Word-specific risk: manual arithmetic. Tax amounts must be typed, and errors compound. If you use Word, add a note to your SOP requiring a calculator check on every invoice before dispatch — or switch to Excel where formulas do this automatically.

Rounding Rule In Practice

Under Rule 50 of the CGST Rules, 2017, rounding applies to the total tax amount on the invoice — not at each line. Sum all line-level CGST, SGST, and IGST amounts, then apply ROUND(total,0). A ₹1,23,456.50 tax total rounds to ₹1,23,457; a ₹1,23,456.40 total rounds to ₹1,23,456.

Frequently Asked Questions About GST Invoice Format In Excel And Word

Can I use a GST invoice format in Excel for e-invoicing businesses?

No. If your aggregate turnover crosses the e-invoicing threshold, you must generate invoices through the IRP to receive an IRN. The Excel format can be used as a pre-generation draft or for invoices outside e-invoicing scope — for example, supplies to unregistered buyers, exempted supplies, and certain exempt categories like banking companies and insured persons. The IRP-generated invoice with QR code is the legally valid document.

How do I handle HSN digit count in a GST invoice format in Excel?

Add a lookup column that checks turnover tier and returns the required digit count — 4 digits for turnover up to ₹5 crore (B2B), 6 digits for turnover above ₹5 crore. Use a dropdown master list of HSN codes pre-loaded with the correct digit count for your business, so your team cannot type a 2-digit or 8-digit code by mistake.

Variations That Change The GST Invoice Format

Export Invoices

An export invoice must carry one of two legends depending on the IGST treatment chosen:

Without payment of IGST (LUT/bond): “Supply meant for export/supply to SEZ unit or SEZ developer for authorised operations under bond or Letter of Undertaking without payment of integrated tax.”
With payment of IGST: “Supply meant for export/supply to SEZ unit or SEZ developer for authorised operations on payment of integrated tax.”

The legend must appear on the face of the invoice. Additionally, the PoS for export is outside India — the invoice should reflect this. For export of goods, e-invoicing requirements apply if the supplier crosses the applicable turnover threshold; the IRP accepts export invoice types.

Currency: Show the invoice value in the foreign currency if the contract is in foreign currency, alongside the INR equivalent using the RBI reference rate on the date of supply.

Reverse Charge Mechanism (RCM) Invoices

Where tax is payable by the recipient, the supplier's invoice must state “Tax payable on reverse charge basis” prominently (Rule 46(n), CGST Rules, 2017). The supplier does not charge or collect tax — the tax line on the invoice shows ₹0 for GST, with the RCM declaration instead.

If the supplier is an unregistered person — for example, a lawyer providing legal services — the registered recipient must issue a self-invoice under Section 31(3)(f) of the CGST Act, 2017 on the same day as the payment or supply, whichever is earlier. The self-invoice follows the same Rule 46 format, with the recipient acting as the supplier for this purpose.

Composition Taxpayers — Bill Of Supply

A composition taxpayer cannot issue a tax invoice. They issue a “Bill of Supply” instead, which must carry the declaration: “Composition Taxable Person, not eligible to collect tax on supplies” (Rule 49, CGST Rules, 2017). No GST is charged or shown on a Bill of Supply. If a composition taxpayer accidentally issues a tax invoice and collects GST, they must deposit that GST to the government and cannot retain it.

B2C Dynamic QR Code

Registered persons with aggregate turnover above ₹500 crore in any preceding financial year from FY 2017–18 must display a dynamic QR code on B2C invoices. The QR code encodes the payment details — UPI ID, bank account, IFSC, and payable amount — enabling the buyer to pay directly. This requirement does not apply to supplies made through e-commerce operators or where the customer has already paid digitally before the invoice is issued.

B2B vs B2C — The Key Structural Difference

For B2B invoices, the recipient's GSTIN is mandatory and drives ITC. For B2C invoices, GSTIN is absent — but for values at or above ₹50,000, you must capture the buyer's name, address, delivery address, and State code. Below ₹50,000 to unregistered buyers, these fields are optional. For daily B2C sales below ₹200 per transaction, a consolidated invoice for all such supplies in a single day is permitted — you do not need an individual invoice per sale.

Frequently Asked Questions About GST Invoice Format Variations

Does a composition taxpayer need to mention GSTIN on a Bill of Supply?

Yes. A composition taxpayer is still a registered person with a valid GSTIN, and the Bill of Supply must carry the supplier's name, address, and GSTIN. The difference is that no tax amount is charged, and the mandatory declaration about composition status replaces the tax computation block (Rule 49, CGST Rules, 2017).

When does an inter-State supply become B2B for invoice format purposes?

The supply is B2B whenever the recipient is a registered person, irrespective of the transaction value. Registration status, not value, determines B2B classification. Once B2B, the invoice must carry the recipient's GSTIN, the correct PoS with State code, and IGST computation if inter-State. The ₹50,000 threshold applies only to unregistered recipients.

Numbering, HSN, PoS, Copies, And Timing — Rules That Create Notices

Serial Number Rules That Attract Scrutiny

The invoice serial number must satisfy four conditions simultaneously (Rule 46(b), CGST Rules, 2017):

Consecutive within a series
Unique for the financial year
Not more than sixteen characters
Contains only alphabets, numerals, hyphens, or slashes

What goes wrong: Teams use a software-generated number that includes spaces, brackets, or special characters. Or they reset numbering mid-year without declaring a new series. A break in the consecutive sequence — for example, INV-100 followed by INV-102 with no INV-101 — triggers a mismatch query in reconciliation.

Allowed example: INV/2025-26/0001. Not allowed: INV 2025-26 001 or INV#2025-26-001.

HSN/SAC Digit Count By Turnover

Above ₹5 crore aggregate turnover: 6-digit HSN on all invoices — B2B and B2C.
₹5 crore or below: 4-digit HSN on B2B invoices; B2C invoices are currently exempt from HSN display at this tier.
All tiers: SAC follows the same digit rule.

A common error: printing only the first 4 digits of a 6-digit HSN for a high-turnover business because the template was built years ago.

Place Of Supply On Inter-State Invoices

For any supply crossing a State boundary, the PoS field must show the State name and two-digit State code — for example, “Karnataka (29)” or “Maharashtra (27)”. Showing only the name or only the code is non-compliant (Rule 46(l), CGST Rules, 2017).

The ITC risk: If your invoice shows the wrong PoS, the IGST flows to the wrong State. Correction requires a credit note and a revised invoice.

Timing Of Invoice Issuance

Goods, movement involved: Before or at the time of removal.
Goods, no movement: At the time of delivery or availability.
Services, general: Within 30 days of the date of supply of service.
Services, banking/insurance/NBFC: Within 45 days of the date of supply.
Continuous supply of services: On or before the due date of payment as per contract, or on receipt of payment if no due date is specified.

Copies Required Under Rule 48

Goods: Three copies — Original for buyer, Duplicate for transporter, Triplicate for supplier.
Services: Two copies — Original for buyer, Duplicate for supplier.

For e-invoices, the IRP-generated document with IRN and QR code replaces the physical copy requirement.

Penalties For Non-Compliance

An incorrect or incomplete invoice is a contravention of the CGST Act. The general penalty under Section 125 of the CGST Act, 2017 is up to ₹25,000 per contravention. Issuing a tax invoice without an actual supply, or fraudulently claiming ITC based on such an invoice, attracts higher penalties and prosecution under Section 122.

Once invoices go out, AiA's bank and credit card statement ingestion and bill-wise allocation auto-map incoming receipts to the correct invoice reference in Tally. This keeps AR ageing accurate and ensures every settled invoice is closed — reducing the manual matching work that leads to missed receipts and stale open items.

Frequently Asked Questions About GST Invoice Rules That Create Notices

Can I use the same invoice series for multiple GSTINs under one PAN?

No. Each GSTIN is a separate registered entity for GST purposes. Invoice series are unique per GSTIN per financial year. If your business has two GSTINs — for example, one for Maharashtra and one for Karnataka — each must maintain its own independent, non-overlapping invoice numbering series.

What if I issued an invoice with the wrong HSN code and the buyer already claimed ITC?

The supplier should issue a credit note cancelling the original invoice and reissue a corrected invoice with the right HSN. The buyer should reverse the ITC claimed on the incorrect invoice in their GSTR-3B for the period when the error is discovered, then re-claim after the corrected invoice appears in GSTR-2B.

How To Lock The GST Invoice Format In Tally: A Control Checklist

Enable And Configure GST Features In TallyPrime

Step 1 — Enable GST: Gateway of Tally > F11 (Features) > Taxation > Enable Goods and Services Tax (GST). Set the State, registration type, and GSTIN.

Step 2 — Set GSTIN and State at company level: The company-level GSTIN populates the supplier block on every invoice automatically. If your business has multiple GSTINs across States, create separate companies — one per GSTIN.

Step 3 — Configure the tax rate structure: Create separate ledgers for CGST, SGST, IGST, and UTGST under Duties and Taxes. Link each ledger to the correct tax type so the right component appears on the invoice based on PoS logic.

Party Master Hygiene — The Single Biggest Control

Every customer and vendor master in TallyPrime must carry:

Legal name, exact match with GST registration certificate
GSTIN, 15 characters, validated format
Registered State, drives the CGST/SGST vs IGST split automatically
Mailing address, pinned to the registered address for the invoice header

Audit your party masters quarterly. GSTIN status can change — a customer may cancel registration or migrate to composition. A stale “Registered” tag on a cancelled GSTIN means your GSTR-1 data is wrong from the first invoice of the period.

HSN/SAC At Stock Item Level

Set the HSN code at the stock item or service ledger level, not at the voucher level. When HSN is set per item, TallyPrime populates it automatically and includes it in the HSN-wise summary in GSTR-1. A voucher-level HSN entry is manual, error-prone, and easy to skip.

Bill-Wise Entry And Advance Adjustment

Enable bill-wise entry under F11 > Accounting Features > Maintain Bill-wise Details. This forces every sales and purchase transaction to reference a bill number — which is the invoice serial number. For advances, record a receipt voucher as “Advance” and later adjust it against the tax invoice using “Against Reference”.

Print Controls — PoS, HSN, And Reverse Charge On The Invoice

Enable “Print HSN/SAC Details” to display the HSN summary block.
Enable “Print Place of Supply” to print the PoS with State code for inter-State invoices.
For RCM invoices, mark the voucher as “Is Reverse Charge Applicable? Yes” to print the RCM declaration.

Frequently Asked Questions About Tally Settings For GST Invoices

How do I stop TallyPrime from splitting a single invoice into CGST/SGST when it should be IGST?

This is a State mismatch between the company's registered State and the party master's registered State. TallyPrime determines the tax type based on PoS logic: if supplier State and PoS match, it applies CGST/SGST; if they differ, it applies IGST. Correct the party master's State; the tax split will update on the next invoice automatically.

Can TallyPrime validate that an invoice serial number does not exceed sixteen characters?

TallyPrime does not enforce the sixteen-character limit natively. Set voucher numbering to Automatic with a concise prefix and a four-digit sequence, keeping the total length predictable. If you use manual numbering, add an external validation step — for example, an Excel check — before GSTR-1 submission.

References

Frequently Asked Questions

What is the difference between a GST tax invoice and a Bill of Supply?

A GST tax invoice is issued by a regular registered taxpayer and includes GST — split across CGST, SGST, IGST, or UTGST. A Bill of Supply is issued by composition taxpayers and for exempt supplies; it carries no GST and must include the declaration “Composition Taxable Person, not eligible to collect tax on supplies.” Buyers cannot claim ITC from a Bill of Supply.

I issued an invoice with the wrong PoS — can I correct it without a credit note?

No. An incorrect PoS changes the tax head. Issue a credit note against the original invoice, reissue a corrected invoice with the right PoS, and amend GSTR-1 in the next filing period. The buyer should reverse and re-claim ITC accordingly.

How many copies of a GST invoice do I need to keep for an audit?

For goods: Original for buyer, Duplicate for transporter, Triplicate for supplier. For services: Original for buyer, Duplicate for supplier. For e-invoices, retain the IRP-generated invoice with IRN digitally. Records must generally be retained for six years from the due date of filing the annual return for the relevant year.

Does GST law require me to issue an invoice if the sale is below ₹200 to an unregistered buyer?

For B2C supplies below ₹200 per transaction where the recipient does not require an invoice, you may issue a single consolidated invoice for all such supplies in a day. This does not apply to B2B sales regardless of value.

What is the penalty if I issue a GST invoice with an incorrect GSTIN for the supplier?

A wrong supplier GSTIN makes the invoice deficient. The general penalty under Section 125 of the CGST Act is up to ₹25,000 per contravention. Practically, it also risks the buyer’s ITC, leading to reversal demands and disputes until corrected.

Can I issue a single invoice for multiple delivery addresses for the same registered buyer?

No. Each distinct PoS, corresponding to each delivery State, requires a separate invoice. Mixing multiple States on one invoice creates PoS ambiguity and reconciliation issues.

What changes on a GST invoice when e-invoicing applies to my business?

When e-invoicing applies, you must upload invoice data to the IRP and print the IRN and QR code on the invoice. The underlying Rule 46 fields remain the same; a physical signature on the printed e-invoice is not required because the IRP’s digital signature in the QR code fulfils authentication.

What is a self-invoice under GST and when must I issue one?

A self-invoice is issued by a registered recipient for supplies received from an unregistered supplier under RCM. Issue it on the date of receipt of goods or services, mark “Tax payable on reverse charge basis,” pay the tax in cash, and claim eligible ITC in the same period.

Written By

Rohan Sinha

Rohan Sinha is a fintech and growth leader building aiaccountant.com, focused on simplifying accounting and compliance for Indian businesses through automation. An IIT BHU alumnus, he brings hands-on experience across 0 to 1 product building, growth, and strategy in B2B SaaS and fintech.