GST Invoicing Services

GST Invoicing is the foundational compliance of every registered business under the Goods and Services Tax regime in India — governed by Sections 31, 32, 33, and 34 of the CGST Act, 2017 read with Rules 46 to 55A of the CGST Rules, 2017. A GST invoice is not merely a commercial billing document; it is a statutory tax instrument that determines the time of supply, triggers output tax liability for the supplier, establishes input tax credit (ITC) entitlement for the recipient under Section 16, and forms the primary data source for GSTR-1, E-Way Bill, e-invoice, and downstream buyer reconciliation. A single defective invoice — wrong HSN, incorrect GSTIN, missing signature, wrong place of supply, or non-compliant serial — can break the ITC chain for the recipient, invite penalty under Section 122, and become the starting point of departmental disputes years later.

The GST law recognises multiple invoice types — Tax Invoice for taxable supplies, Bill of Supply for exempt / composition supplies, Receipt Voucher for advances, Payment Voucher for RCM payments, Refund Voucher where advance is returned, Revised Invoice for pre-registration supplies, Credit Note and Debit Note under Section 34 for post-issue adjustments, and Delivery Challan for movement without supply. Every document type carries its own mandatory fields, time limits, serial-number discipline, and downstream reporting requirements. Overlaying this are additional layers — e-invoicing and dynamic QR codes for notified turnover classes, HSN disclosure rules, place of supply rules for inter-state vs intra-state tax determination, and RCM identification for specified supplies.

Our GST Invoicing Services provide end-to-end support — from invoice format design, serial-number and document-series setup, HSN / SAC mapping, place of supply logic, template creation for all document types, ERP / Tally / Zoho integration, e-invoice and E-Way Bill linkage, credit / debit note workflows, and reconciliation with GSTR-1 and books — so that every invoice issued is legally valid, commercially strong, and ready to stand up to both buyer scrutiny and departmental audit.

16 Fields

Mandatory invoice particulars

8 Documents

Invoice / voucher / note types

30 / 45 Days

Service invoice timelines

Unique Serial

Max 16 chars, per FY

Laws & Frameworks We Work Under

CGST Act – Sec 31

CGST Act – Sec 32 / 33 / 34

CGST Rules – Rule 46

CGST Rules – Rule 47 / 48

CGST Rules – Rule 49 / 50 / 51

CGST Rules – Rule 53 / 54 / 55

HSN / SAC Rules

Place of Supply – Sec 10 / 12 / 13

Main Invoice Categories Under GST

Primary

Tax Invoice

Standard invoice for taxable outward supplies under Section 31 and Rule 46.

B2B tax invoice
B2C large / small
Export invoice
SEZ invoice
Deemed export invoice
Mandatory 16 fields

Exempt / Composition

Bill of Supply

Document issued for exempt supplies and by composition taxpayers under Section 31(3)(c).

Exempt supplies
Composition dealers
No tax charged
"Composition taxable person"
Rule 49 compliance
Separate serial series

Vouchers

Receipt, Payment & Refund Vouchers

Vouchers for advances received, RCM payments, and refund of advances under Section 31.

Receipt voucher (advance)
Payment voucher (RCM)
Refund voucher (return)
Rule 50 / 52 / 51 compliance
Time of supply trigger
GSTR-1 Table 11

Adjustments

Credit & Debit Notes

Post-issue adjustment notes under Section 34 for value, tax, or quantity changes.

Credit note
Debit note
Original invoice linkage
Sales return
Post-sale discount
November 30 cut-off

Movement

Delivery Challan

Non-supply movement document under Rule 55 for job work, transfers, and line sales.

Job work dispatch
Branch transfer
Line sales
Exhibition movement
Multi-vehicle knock-down
E-Way Bill linkage

Special

Revised & Special Invoices

Revised invoices, ISD invoices, and sector-specific invoices under Rules 53 / 54.

Revised invoice (pre-reg)
ISD invoice
Banking / NBFC invoice
GTA consignment note
Passenger transport ticket
Self-invoice (URD RCM)

Key Invoice Fields & Concepts at a Glance

Identification

Name, Address & GSTIN

Supplier name, address, and GSTIN along with recipient details for B2B invoices.

Supplier Recipient

Serial

Unique Invoice Number

Consecutive serial not exceeding 16 characters — alphanumeric, unique per financial year.

Max 16 Per FY

HSN / SAC

HSN / SAC Code

4, 6, or 8-digit HSN / SAC disclosure based on turnover slab as notified by CBIC.

4 / 6 / 8 Digits Mandatory

Place of Supply

POS & State Code

Place of supply determines CGST+SGST or IGST — governed by Sections 10 / 12 / 13.

Intra-State Inter-State

Tax Breakup

CGST / SGST / IGST / Cess

Separate disclosure of taxable value, rate, and tax amount for each head — with cess where applicable.

Rate-wise Per Line

Time Limit

Invoice Timing

Goods — before / at time of removal; Services — within 30 days (45 days for BFSI).

30 Days 45 Days BFSI

Signature

Digital / Physical Signature

Invoice must be signed — physical signature or DSC / electronic signature by authorised person.

DSC Physical

QR / IRN

E-Invoice & Dynamic QR

IRN + signed QR for B2B under Rule 48(4); dynamic QR on B2C for notified taxpayers.

B2B IRN B2C QR

What Our GST Invoicing Engagement Covers

Design

Invoice Design & Setup

Legally-compliant invoice templates, serial series, and master data setup across entities.

Tax invoice template
Bill of Supply template
Voucher templates
Serial-number logic
HSN / SAC master
POS master

Integration

ERP / Software Integration

Tally, Zoho, Busy, SAP, Oracle, and custom ERP integration with e-invoice and EWB linkage.

Tally / Zoho / Busy
SAP / Oracle / MS Dynamics
E-invoice API
E-Way Bill API
Print template design
QR code embedding

Run

Daily Ops & Reconciliation

Day-to-day invoice issuance, credit / debit note workflows, and reconciliation with GSTR-1.

Invoice vs GSTR-1 match
Invoice vs IRN match
Invoice vs EWB match
CN / DN workflow
November 30 cut-off
Exception tracking

Our GST Invoicing Services

Invoice Template Design

Legally-compliant tax invoice, Bill of Supply, and voucher templates with branding.

Serial Number & Series Setup

Document-series design — per GSTIN, per location, per vertical — compliant with Rule 46.

HSN / SAC Mapping

Item-level HSN / SAC mapping with rate tagging and turnover-based disclosure compliance.

Place of Supply Logic

Configuration of POS rules to automatically apply CGST+SGST or IGST based on Sections 10 / 12 / 13.

E-Invoice & EWB Linkage

IRN generation, QR embedding, and E-Way Bill Part A auto-fill in a single invoicing flow.

Credit / Debit Note Workflow

Structured workflow for CN / DN under Section 34 with November 30 cut-off tracking.

RCM & Self-Invoice

Self-invoicing for URD RCM, ISD invoices, and cross-charge invoices between distinct persons.

Audit-Ready Archival

Invoice archival, GSTR-1 reconciliation, and audit-ready documentation for Section 35 compliance.

When You Need Expert GST Invoicing Support

New Registration

Newly-registered business setting up invoicing from scratch with correct formats and series.

E-Invoice Go-Live

Turnover crossing e-invoicing threshold requiring IRN-linked invoicing integration.

Multi-GSTIN Setup

Multiple GSTINs across states needing consistent invoice templates and coordinated series.

ERP Migration

Migration from Tally / Zoho / legacy system to SAP / Oracle / custom ERP with clean invoicing config.

High CN / DN Volume

Heavy sales returns, post-sale discounts, or rate adjustments requiring disciplined CN / DN workflows.

Exports & SEZ

Export / SEZ invoicing with LUT, shipping bill linkage, and ICEGATE reconciliation.

RCM / Cross-Charge

Businesses with significant RCM, ISD, and inter-branch cross-charge invoicing needs.

Past ITC Disputes

Prior disputes with buyers or notices on ITC eligibility due to invoicing defects.

Information & Documents Needed

Entity Data

GSTIN certificate
PAN of entity
Business address proof
Authorised signatory list
Board resolution / POA
DSC of signatory
Logo / brand guidelines

Master Data

Customer / vendor master
Item / service master
HSN / SAC mapping
Tax rate master
UoM (GSTN codes)
Place of supply master
Location / branch list

Operational & IT

Current invoice samples
ERP / accounting details
E-invoice credentials
EWB credentials
Print template designs
Approval / workflow rules
Archival policy

Our End-to-End Invoicing Approach

Assessment

Current-state review, gap analysis, and mapping to Section 31 & Rule 46 requirements.

Design & Masters

Invoice template design, serial-series logic, HSN / SAC and POS master setup.

Integration & UAT

ERP integration, e-invoice / EWB linkage, UAT with sample transactions.

Go-Live & Training

Phased go-live with user training on invoice creation, CN / DN, and edge cases.

Run & Reconcile

Monthly reconciliation with GSTR-1, IRN, EWB, and books; continuous improvement.

Why Choose Us for GST Invoicing

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Rule 46 compliant templates

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All document types covered

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Seamless ERP integration

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E-invoice + EWB in one flow

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Accurate POS determination

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CN / DN discipline

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Multi-GSTIN scale-ready

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Audit-ready documentation

FAQs on GST Invoicing

What are the mandatory particulars on a GST tax invoice?

Rule 46 of the CGST Rules prescribes the mandatory particulars of a tax invoice. These include the name, address, and GSTIN of the supplier; a consecutive serial number not exceeding 16 characters (alphanumeric, unique per financial year); the date of issue; name, address, and GSTIN of the recipient (for B2B); HSN code of goods or SAC of services; description of goods or services; quantity and unit of measure; total value, taxable value, and any discount; rate and amount of CGST, SGST, IGST, and cess separately; place of supply with state name and code for inter-state supplies; address of delivery where different from place of supply; whether tax is payable on reverse charge; and signature or digital signature of the supplier or authorised representative. Missing or incorrect particulars can invalidate the invoice for ITC purposes and attract penalty under Section 122.

What is the time limit for issuing a GST invoice?

Under Section 31 of the CGST Act, in the case of supply of goods, the tax invoice must be issued before or at the time of removal of goods for supply to the recipient (where supply involves movement) or delivery of goods / making available to the recipient (in other cases). In the case of supply of services, the invoice must be issued within 30 days from the date of supply of service, extended to 45 days for banking companies, financial institutions, NBFCs, and insurers. For continuous supply of goods or services, separate rules apply tied to statements of account, successive payments, or milestones. Breach of these timelines creates a disconnect between time of supply, invoice date, and GSTR-1 reporting — and can trigger interest and penalty exposure.

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

A tax invoice is issued by a regular registered taxpayer for taxable outward supplies, and it charges CGST + SGST / IGST separately — forming the basis of ITC for the recipient. A Bill of Supply, on the other hand, is issued in two specific scenarios under Section 31(3)(c) and Rule 49: first, when a registered person makes an exempt supply (including nil-rated and non-GST supplies), and second, when a composition taxpayer under Section 10 makes any outward supply. A Bill of Supply does not charge GST and therefore cannot be used by the recipient to claim ITC. A composition dealer must also mention "composition taxable person, not eligible to collect tax on supplies" on every Bill of Supply issued. The two document types must be maintained in separate serial series.

When should credit notes and debit notes be issued under GST?

Under Section 34 of the CGST Act, a credit note is issued by the supplier where the taxable value or tax charged in a tax invoice is found to exceed the amount actually payable — typically for sales returns, post-sale discounts satisfying Section 15(3) conditions, deficient services, or erroneous over-billing. A debit note is issued where the taxable value or tax charged is less than the amount actually payable — typically for short-billing, rate corrections, or additional supplies against the same invoice. Critical time limit: credit notes can be issued and declared in GSTR-1 up to 30th November of the following financial year or the date of filing the annual return, whichever is earlier, under Section 34(2) — beyond this, the tax liability adjustment is no longer available, and the taxpayer bears the cost.

What are the HSN / SAC disclosure requirements on invoices?

HSN disclosure on invoices is mandated based on the aggregate turnover of the registered person in the preceding financial year. Under current CBIC notifications, taxpayers with aggregate turnover up to Rs. 5 crore are required to mention 4-digit HSN codes on B2B invoices (optional on B2C), while taxpayers with aggregate turnover above Rs. 5 crore must mention 6-digit HSN codes on all tax invoices. Notified exporters and specified chemical / notified commodity taxpayers may be required to disclose 8-digit HSN. For services, the corresponding SAC codes apply. These requirements are updated periodically — incorrect or missing HSN can attract penalty under Section 125 (general penalty up to Rs. 25,000) and disrupts GSTR-1 HSN Summary reporting (Table 12) and buyer-side ITC matching.

What is self-invoicing and when is it required?

Self-invoicing is required under Section 31(3)(f) of the CGST Act and Rule 46 when a registered person receives a supply of goods or services from an unregistered person, and tax is payable under reverse charge (URD RCM) under Section 9(3) or Section 9(4). In such cases, the recipient cannot obtain a tax invoice from the URD supplier, so the recipient itself raises a tax invoice — called a "self-invoice" — for the supply received, along with a payment voucher under Section 31(3)(g) at the time of making payment. The self-invoice supports the RCM liability declared in GSTR-3B and the corresponding ITC claim. Common scenarios include procurement from unregistered GTAs, unregistered advocates, government supplies under notified categories, and specified agricultural / forestry supplies.

What is the difference between a delivery challan and a tax invoice?

A tax invoice is issued for an actual supply of goods or services and creates tax liability; a delivery challan, on the other hand, is issued under Rule 55 for the movement of goods where the transaction is not a supply — so no tax is charged. Common scenarios for delivery challans include: movement of goods for job work, transportation of goods in semi-knocked-down or completely-knocked-down condition (with a single tax invoice and multiple delivery challans for each consignment), branch / depot transfers within the same GSTIN, goods sent on approval or for exhibition, and movement for testing or repair. A delivery challan is required to accompany the consignment for E-Way Bill compliance in such cases. Where the transaction subsequently qualifies as a supply, a tax invoice must be issued at the appropriate time of supply.

How many copies of an invoice must be issued and maintained?

Under Rule 48 of the CGST Rules, for supply of goods, the invoice must be prepared in triplicate — the original for the recipient, the duplicate for the transporter (marked "Duplicate for Transporter"), and the triplicate for the supplier (marked "Triplicate for Supplier"). For supply of services, the invoice must be prepared in duplicate — the original for the recipient and the duplicate for the supplier. In practice, for e-invoiced transactions the physical multi-copy requirement is relaxed because the IRN and signed QR code on a single copy carry the legal equivalence. Section 35 read with Rule 56 requires the supplier to preserve these records for at least 72 months from the due date of the annual return — which translates to roughly 6 years, extended where any proceedings are pending.

Every Invoice Legally Valid, Commercially Strong

Partner with our specialists for end-to-end GST Invoicing Services — templates, ERP integration, e-invoice, E-Way Bill, CN / DN, and reconciliation — under one roof.

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