How to Generate E-Invoice on GST IRP Portal (Step by Step Guide)

E-invoicing under GST requires businesses with aggregate turnover above ₹5 crore to register each B2B invoice on the Invoice Registration Portal (IRP) at einvoice1.gst.gov.in before issuing it to the buyer. The IRP validates the invoice data, generates a unique 64-character Invoice Reference Number (IRN), digitally signs the invoice, and returns a QR code for verification. This guide walks through the complete process: registering on the e-invoice portal, preparing invoice data in JSON format, uploading to the IRP, receiving the IRN, and managing cancellations and errors. The entire generation process takes under 5 minutes per invoice on the web portal and under 2 seconds via API.

What is E-Invoicing Under GST?

E-invoicing (electronic invoicing) under GST is a government-mandated system where specified businesses must report their B2B tax invoices to the Invoice Registration Portal (IRP) for validation, digital signing, and assignment of a unique Invoice Reference Number (IRN) before issuing the invoice to the buyer. E-invoicing does not create a new invoice; it authenticates the existing invoice through the centralised IRP system.

The GST Council introduced e-invoicing in India through Notification No. 68/2019 (Central Tax) dated 13 December 2019, with phased implementation starting from 1 October 2020 for businesses with turnover exceeding ₹500 crore. Since then, the government has progressively reduced the turnover threshold: ₹100 crore from 1 January 2021, ₹50 crore from 1 April 2021, ₹20 crore from 1 April 2022, ₹10 crore from 1 October 2022, and finally ₹5 crore from 1 August 2023. Each reduction brings more businesses under the e-invoicing mandate, and the government may lower the threshold further to include smaller businesses. The e-invoicing system is governed by Rule 48(4) of the CGST Rules, 2017 and administered by the GSTN through the NIC-operated IRP.

The core purpose of e-invoicing is threefold: eliminate manual data entry errors in GST return filing, reduce tax evasion through real-time invoice reporting, and create a unified digital record of every B2B transaction across India. When you generate an e-invoice, the IRP sends the validated data to the GST portal, where it auto-populates your GSTR-1 return. The buyer's GSTR-2A/2B is also updated simultaneously, enabling real-time Input Tax Credit reconciliation. For transactions requiring goods transport, Part A of the E-Way Bill is auto-populated from the e-invoice data, eliminating the need for separate e-way bill generation for the invoice portion.

Who Must Generate E-Invoices in 2026?

E-invoicing applicability depends on your aggregate turnover in any financial year since 2017-18. If your business crossed the threshold in even one year, e-invoicing remains mandatory regardless of current year turnover. Understanding this rule is critical because many businesses incorrectly assume that a dip in current-year turnover exempts them from the requirement.

Turnover Threshold Timeline

How to Check Your Applicability

Calculate your aggregate turnover for each financial year from 2017-18 to the current year. Aggregate turnover includes the total value of all taxable supplies (excluding inward supplies under reverse charge), exempt supplies, exports, and inter-state supplies of persons with the same PAN, computed on an all-India basis. If this figure exceeds ₹5 crore in any single financial year, e-invoicing is mandatory for your business. Cross-check your turnover figures from your GSTR-9 annual returns or audited financial statements. The e-invoice portal auto-verifies turnover data from the GST system, and your registration will be rejected if the system does not reflect eligible turnover.

Entities Exempt from E-Invoicing

Certain categories are exempt from e-invoicing regardless of turnover: Special Economic Zone (SEZ) units (not SEZ developers), insurance companies, banking companies and financial institutions (including NBFCs), Goods Transport Agencies (GTAs), passenger transport service providers, and entities providing cinema ticket services. These exemptions are specified under Notification No. 13/2020 (Central Tax) as amended. If your business falls under an exempt category, you are not required to generate e-invoices even if your turnover exceeds ₹5 crore.

E-Invoice Applicability: Covered and Exempt Transactions

Not all transactions require e-invoicing. The mandate applies to specific supply types, and understanding the distinction prevents both over-compliance and non-compliance penalties.

Transactions Requiring E-Invoicing

• B2B supplies: All supplies where both the supplier and recipient are GST-registered (tax invoices with buyer GSTIN)
• Exports: Export invoices for goods or services, both with payment (EXPWP) and without payment of tax (EXPWOP) under Bond/LUT
• Supplies to SEZ: Invoices to SEZ developers and SEZ units, with or without payment of IGST
• Deemed exports: Supplies to Export Oriented Units (EOUs) and under specific deemed export provisions
• Credit notes and debit notes: Issued against B2B invoices, exports, and SEZ supplies

Transactions Exempt from E-Invoicing

• B2C supplies: Sales to unregistered consumers (no buyer GSTIN)
• Import transactions: Bills of entry processed through customs do not go through IRP
• Nil-rated and exempt supplies: Goods and services with 0% or exempt GST rate
• Reverse charge supplies: Where the recipient pays GST (no supplier invoice on IRP)
• Delivery challans: Non-invoice documents for job work, sample movement, or inter-branch transfers
• Bill of supply: Issued by composition scheme dealers or for exempt goods

How the IRP System Works

Understanding the technical flow helps you troubleshoot errors and choose the right generation method. The IRP is not a storage system; it is a validation and registration service that processes each invoice in real time.

The e-invoice lifecycle follows six stages. First, the supplier creates the invoice in their accounting software with all mandatory fields. Second, the software exports the invoice data in the GST e-invoice JSON schema (version 1.1). Third, the JSON data is transmitted to the IRP, either manually (web upload) or programmatically (API call). Fourth, the IRP validates the data: checks GSTIN validity, verifies HSN codes against the master list, confirms the invoice number is unique for the supplier-year combination, validates mathematical calculations (taxable value, tax amounts, total), and ensures schema compliance. Fifth, upon successful validation, the IRP generates the IRN (a SHA-256 hash of supplier GSTIN + invoice number + financial year), digitally signs the invoice payload, generates a QR code containing key invoice parameters, and returns all three to the supplier. Sixth, the IRP simultaneously pushes the validated invoice data to the GST portal (for GSTR-1 auto-population) and the E-Way Bill system (for Part A auto-fill). The entire process from submission to IRN receipt takes under 2 seconds for API calls and under 5 seconds for web submissions.

Prerequisites Before Generating E-Invoices

Complete these prerequisites before your first e-invoice generation. Missing any of these causes delays or errors during the process.

Technical Requirements

1. Active GSTIN: Your GST registration must be active (not suspended, cancelled, or pending). Verify status at gst.gov.in under 'Search Taxpayer'.
2. E-Invoice Portal Registration: One-time registration at einvoice1.gst.gov.in (separate from GST portal login). This takes 10 to 15 minutes.
3. Compatible Accounting Software: Your invoicing software must support JSON export in e-invoice schema version 1.1, or you must use the IRP web form for manual entry.
4. HSN/SAC Code Master: Maintain a validated HSN/SAC code list for all your products and services. Codes must be 4-digit (turnover up to ₹5 crore) or 6-digit (turnover above ₹5 crore).
5. Buyer GSTIN Verification: Verify each buyer's GSTIN status before invoice creation. Invalid or cancelled GSTINs cause e-invoice rejection.

For API Integration (Additional Requirements)

1. Static IP address: Your server must have a static public IP for API access. Dynamic IPs are not supported.
2. API credentials: Register for API access on the e-invoice portal to obtain Client ID and Client Secret.
3. IP whitelisting: Add your server IP under 'API Registration' on the portal. Allow 30 minutes for propagation.
4. SSL certificate: API calls must use HTTPS. Your server needs a valid SSL certificate.

Step-by-Step: Generate E-Invoice on the IRP Portal

This section covers the complete process across 6 steps, from portal registration to sharing the validated e-invoice with the buyer. Total setup time for first-time users is 1 to 3 hours. Subsequent invoice generation takes under 5 minutes per invoice via the web portal.

Step 1: Register on the E-Invoice Portal

Open einvoice1.gst.gov.in in your browser. Click 'Registration' in the top menu, then select 'Portal Login'. Enter your 15-digit GSTIN in the search field. The system auto-fetches your business details (legal name, trade name, address, email, and mobile number) from the GST common portal. Verify that the auto-populated details are correct. Set a username (alphanumeric, 8 to 15 characters) and a strong password (minimum 8 characters with uppercase, lowercase, number, and special character). The portal sends an OTP to your GST-registered mobile number and email address. Enter both OTPs within 10 minutes to complete registration. You will receive a confirmation message with your login credentials. Save these credentials securely, as you need them for every e-invoice generation session. Registration is a one-time process; you do not need to register again for subsequent logins.

Step 2: Configure Your Generation Mode

After logging in, choose how you will generate e-invoices. The e-invoice portal supports four modes, each suited to different business volumes and technical capabilities.

For API integration, navigate to 'API Registration' after logging in. Click 'Create API User', enter your static IP address, and submit. The portal generates your Client ID and Client Secret. Store these credentials securely in your ERP system's configuration. You can whitelist up to 5 IP addresses. For production API access, your ERP developer will use these credentials along with the IRP API endpoints documented at einvoice1.gst.gov.in/apidocs.

Step 3: Prepare Invoice Data in JSON Schema

Every e-invoice must conform to the e-invoice JSON schema version 1.1 defined by GSTN. The schema contains approximately 140 fields organised into mandatory and optional sections. Your accounting software should handle the JSON generation automatically. If you are using the web portal, you fill in a form, and the portal creates the JSON internally.

Step 4: Upload Invoice Data to the IRP

The upload method depends on your chosen generation mode:

Web Portal (Manual Entry): Log in to einvoice1.gst.gov.in, click 'E-Invoice' in the left menu, then 'Generate New'. Fill in each section of the form: select the supply type (B2B, SEZWP, SEZWOP, EXPWP, EXPWOP), enter document type (INV for invoice, CRN for credit note, DBN for debit note), invoice number, and invoice date. Enter seller details (auto-filled from your registration), buyer GSTIN (the portal auto-fetches buyer name and address), line items with HSN codes, quantities, rates, and tax amounts. The portal calculates totals automatically. Review all fields, then click 'Generate IRN'.

JSON File Upload: Navigate to 'E-Invoice' then 'Generate Bulk' or 'Generate from JSON'. Click 'Choose File', select your JSON file, and click 'Upload'. The system validates the JSON schema and data. If validation passes, you receive the IRN and QR code immediately. If errors exist, the system returns a detailed error report with field-level descriptions.

API Integration: Your ERP system sends an authenticated POST request to the IRP API endpoint (https://einvoice1.gst.gov.in/eicore/v1.03/Invoice) with the JSON payload in the request body. The API response contains the IRN (AckNo), acknowledgement date (AckDt), signed invoice data, signed QR code, and the IRP's digital signature. Your ERP system should store these values against the invoice record.

Step 5: Receive IRN and Digitally Signed QR Code

Upon successful validation, the IRP returns three critical elements: the 64-character Invoice Reference Number (IRN), the digitally signed invoice data (the entire JSON payload with the IRP's digital signature appended), and the signed QR code (containing IRN, supplier GSTIN, buyer GSTIN, document number, invoice date, total value, line item count, main HSN code, and a unique hash). The IRN is generated as a SHA-256 hash of three inputs: your GSTIN, the invoice number, and the financial year. This ensures every valid invoice has a globally unique identifier. Download or store the IRN acknowledgement for your records. The IRP simultaneously transmits the validated e-invoice data to the GST portal for GSTR-1 auto-population and to the E-Way Bill system for Part A auto-fill.

Step 6: Print and Share the E-Invoice

After receiving the IRN and QR code, embed them into your invoice document before sharing with the buyer. The printed invoice must display the IRN (either as text or embedded in the QR code) and the QR code prominently. Most accounting software automatically appends the IRN and QR code to the invoice PDF after IRP validation. Share the invoice with the buyer through your regular channel (email, print, or electronic). The buyer can scan the QR code using any QR scanner app to verify the invoice authenticity by checking the IRN against the IRP database. The buyer's GSTR-2A and GSTR-2B are automatically updated with the e-invoice data, enabling them to verify the transaction and claim Input Tax Credit.

E-Invoice Generation Modes Compared

Choosing the right generation mode impacts your operational efficiency. Businesses processing fewer than 50 invoices per month can use the web portal, while high-volume businesses should invest in API integration for long-term productivity gains.

Web Portal: Manual Entry

The web portal at einvoice1.gst.gov.in provides a form-based interface where you manually enter each invoice field. This mode requires no technical setup and works from any browser. Each invoice takes 3 to 5 minutes to complete. The portal validates data in real time, highlighting errors as you fill in each field. This mode is ideal for businesses generating 1 to 50 invoices per month. Limitations include manual data entry overhead, no batch processing, and higher risk of typographical errors.

API Integration: Automated Processing

API integration connects your ERP or accounting software directly to the IRP. Once configured, every invoice created in your software is automatically sent to the IRP, and the IRN and QR code are received without manual intervention. Processing time is under 2 seconds per invoice. API integration requires a developer for initial setup (typically ₹10,000 to ₹50,000 for custom ERP systems) but delivers significant time savings for businesses generating 200+ invoices monthly. Popular accounting software like Tally Prime, Zoho Books, and SAP include pre-built e-invoice API modules.

Bulk Upload: Excel/CSV Method

Download the bulk upload template from the e-invoice portal, fill in invoice details for multiple invoices (up to 500 per file), and upload the completed file. The system processes each row as a separate invoice and returns a result file with IRNs for successful invoices and error details for failed ones. This mode suits medium-volume businesses (50 to 500 invoices per month) using software that cannot generate JSON but can export to Excel. Processing time for a file of 100 invoices is approximately 5 to 10 minutes.

GST Suvidha Providers (GSP)

GSPs are authorised third-party platforms that integrate with the IRP on your behalf. Providers like ClearTax, Masters India, Cygnet, and EY offer cloud-based e-invoicing solutions with additional features: automated JSON generation from your invoice data, error resolution assistance, dashboard and analytics for invoice tracking, bulk processing, and integration with multiple accounting software. GSP plans typically cost ₹500 to ₹5,000 per month depending on invoice volume and features. For businesses without in-house technical capability, a GSP is the most practical choice for reliable e-invoicing.

E-Invoice Data Flow to GSTR-1

One of the most significant benefits of e-invoicing is the automatic population of your GSTR-1 return. E-invoiced transactions flow directly from the IRP to the GST portal without any manual data entry.

GSTR-1 Tables Auto-Populated from E-Invoices

When you file GSTR-1, the e-invoiced transactions appear pre-filled in the respective tables. You can review but cannot edit these auto-populated entries. If corrections are needed, cancel the e-invoice (within 24 hours) or issue a credit/debit note. Non-e-invoiced transactions (B2C sales, exempt supplies) must still be entered manually in GSTR-1. Verify the auto-populated data against your accounting records before filing GSTR-1 to ensure accuracy. Discrepancies typically arise from invoices that were cancelled on the IRP but not reversed in the accounting system, or from credit notes issued manually without IRP reporting.

E-Invoice and E-Way Bill Integration

E-invoicing and the E-Way Bill system are integrated to reduce duplicate data entry. When you generate an e-invoice for a B2B supply that also requires an e-way bill (goods movement worth ₹50,000 or above), Part A of the e-way bill is auto-populated from the e-invoice data.

How the Integration Works

During e-invoice generation, if you fill in the EwbDtls (E-Way Bill Details) section in the JSON, including transporter ID, distance, vehicle number, and mode of transport, the IRP generates both the IRN and the E-Way Bill number (EWB number) simultaneously in a single transaction. You receive both numbers in the IRP response. If you skip the EwbDtls section during e-invoice generation, you can still generate the e-way bill separately on the E-Way Bill portal at ewaybillgst.gov.in. Part A (invoice details) will be pre-filled from the e-invoice; you only need to enter Part B (transport details). This integration saves significant time for businesses that ship physical goods with every invoice, as it eliminates the need to enter invoice details twice on two separate portals.

How to Cancel an E-Invoice

Cancellation rules for e-invoices are strict. The IRP allows cancellation only within a 24-hour window from the time of IRN generation. After 24 hours, indirect cancellation through credit/debit notes is the only option.

Cancellation Within 24 Hours

Log in to einvoice1.gst.gov.in, navigate to 'E-Invoice' then 'Cancel'. Enter the IRN number or search by invoice number and date. The portal displays the invoice details. Select the cancellation reason from the dropdown: duplicate invoice, data entry mistake, order cancelled, or other (with a mandatory remark). Click 'Submit' to cancel. The IRP marks the IRN as cancelled and notifies the GST portal to remove the entry from GSTR-1 auto-population. The cancelled IRN cannot be reused. Generate a new invoice with a fresh invoice number for the corrected/replacement transaction. Cancellation via API is also available by sending a cancellation request with the IRN and reason code.

After 24 Hours: Credit Note / Debit Note

If the 24-hour cancellation window has passed, you cannot cancel on the IRP. Instead, issue a Credit Note (for full or partial value reduction) or Debit Note (for value increase) against the original e-invoice. The credit/debit note must also be reported on the IRP and will receive its own IRN. In the credit note, reference the original invoice number and IRN. The credit note auto-populates GSTR-1 Table 9B, effectively negating or adjusting the original invoice value. Both parties (supplier and buyer) see the credit note reflected in their GST returns. For invoices that need complete cancellation after 24 hours, issue a full-value credit note equal to 100% of the original invoice amount.

Common E-Invoice Errors and How to Fix Them

The IRP validates every field in the invoice data before generating the IRN. Understanding the most frequent error codes and their solutions reduces rejection rates and speeds up your invoice processing.

Error: Duplicate IRN (Error Code 2150)

This error means an invoice with the same combination of supplier GSTIN, invoice number, and financial year already exists on the IRP. The IRN is generated from these three values, so any duplication triggers this error. Resolution: check if the invoice was already reported successfully (search under 'E-Invoice' then 'Search IRN'). If the original needs correction, cancel it within 24 hours and re-generate with the same number, or issue a new invoice with a different invoice number. Ensure your invoice numbering series does not reset within the same financial year.

Error: GSTIN Validation Failed (Error Code 2016/2117)

This error occurs when the buyer's GSTIN is invalid, cancelled, or suspended. The IRP validates buyer GSTIN against the GST common portal in real time. Resolution: verify the buyer GSTIN at gst.gov.in under 'Search Taxpayer'. If the buyer's registration is cancelled, you cannot issue a B2B e-invoice to them. If the GSTIN is temporarily suspended, wait for the buyer to resolve their GST status or issue a B2C invoice if applicable. For new buyers, always verify GSTIN before creating the invoice.

Error: HSN Code Not Found (Error Code 2029)

The IRP maintains a master list of valid HSN codes. This error triggers when the HSN code in your invoice does not match any entry in the master. Resolution: verify the HSN code on the CBIC GST portal at cbic-gst.gov.in under 'HSN Code Search'. Use the correct digit count: 4-digit HSN for turnover up to ₹5 crore, 6-digit HSN for turnover above ₹5 crore. Do not use 2-digit HSN codes as the IRP does not accept them for e-invoicing. If your product is genuinely not classifiable, consult a GST practitioner for the correct HSN classification.

Error: JSON Schema Mismatch (Error Code 2000 Series)

Schema errors arise from incorrect data types, missing mandatory fields, or invalid field values. Common causes include: date format mismatch (use dd/mm/yyyy), state code as text instead of numeric (use 2-digit codes like 27 for Maharashtra), PIN code with fewer than 6 digits, and decimal precision issues in value fields. Resolution: download the e-invoice schema documentation from the portal, compare your JSON structure field by field, and fix the non-compliant values. Use the offline validation tool to catch schema issues before uploading.

Error: Mathematical Mismatch (Error Code 2024/2025)

The IRP independently calculates tax amounts and totals from your line item data and compares them with the values you provide in the ValDtls section. If there is a mismatch (even by ₹1), the invoice is rejected. Resolution: ensure your calculation logic matches the IRP formula: Taxable Value x GST Rate = Tax Amount (CGST + SGST for intra-state, IGST for inter-state). Round each tax component to 2 decimal places. The total invoice value must equal Taxable Value + CGST + SGST + IGST + Cess - Discount + Other Charges.

Penalties for E-Invoice Non-Compliance

The consequences of not generating e-invoices when required are severe, affecting both the supplier and the buyer.

Penalties for the Supplier

Impact on the Buyer

If the supplier does not generate an e-invoice when required, the buyer cannot claim Input Tax Credit (ITC) on that invoice. The GST system treats a non-e-invoiced B2B invoice from an eligible supplier as invalid. The invoice will not appear in the buyer's GSTR-2B (auto-populated ITC statement). Buyers should verify that their suppliers are e-invoice compliant by checking the IRP for the IRN of received invoices. Scan the QR code on any B2B invoice to verify its authenticity against the IRP database.

API Integration: Technical Setup Guide

API integration automates the entire e-invoice generation process, making it the preferred method for businesses processing large volumes of invoices. This section covers the technical setup for developers and ERP administrators.

API Registration Process

1. Log in to einvoice1.gst.gov.in with your registered credentials.
2. Navigate to 'API Registration' in the left menu and click 'Create API User'.
3. Enter your static public IP address (the IP from which API calls will originate). Up to 5 IPs allowed.
4. Submit and receive your Client ID and Client Secret via email.
5. Test connectivity using the sandbox environment before moving to production API calls.

API Authentication Flow

The IRP API uses a two-step authentication process. First, call the authentication endpoint (/eicore/v1.03/auth) with your GSTIN, Client ID, Client Secret, and username. The API returns an AuthToken valid for 6 hours. Second, include this AuthToken in the header of all subsequent API calls (e-invoice generation, cancellation, search). When the token expires, re-authenticate to obtain a new one. Your ERP system should implement automatic token refresh logic to ensure uninterrupted e-invoice generation.

Key API Endpoints

Expert Tips for E-Invoice Implementation

Tip 1: Maintain a Clean HSN/SAC Master

Create a master list of HSN codes for every product and SAC codes for every service your business offers. Validate each code on cbic-gst.gov.in before adding it to your master. Map this master to your product/service catalogue in your accounting software. This one-time setup prevents repeated HSN rejection errors and ensures consistency across all invoices. Review and update the master quarterly as the government periodically adds and modifies HSN codes.

Tip 2: Implement Pre-Upload Validation

Whether you use the web portal, JSON upload, or API, run a validation check on your invoice data before submitting to the IRP. For API users, build a local validation layer that checks mandatory fields, GSTIN format, HSN code validity, and mathematical accuracy. This pre-check catches 90% of errors locally, reducing IRP rejection rates and avoiding the time spent on debugging failed uploads.

Tip 3: Set Up Buyer GSTIN Auto-Verification

Integrate a GSTIN verification step into your invoice creation workflow. Before finalising any B2B invoice, auto-verify the buyer's GSTIN status through the GST search API or the gst.gov.in portal. This prevents invoice rejections caused by invalid, cancelled, or suspended buyer GSTINs. Most accounting software supports GSTIN auto-verification. If yours does not, make it a manual checklist item before invoice creation.

E-Invoicing for Specific Business Scenarios

E-Commerce Sellers

E-commerce sellers (on Amazon, Flipkart, Meesho) with turnover above ₹5 crore must generate e-invoices for their B2B transactions. Marketplace commission invoices received from the platform do not require e-invoicing from the seller's side (the marketplace generates those). However, if you sell to other businesses through the e-commerce platform (B2B orders), those invoices require e-invoicing. Coordinate with the platform's invoicing system to ensure e-invoice data flows correctly.

Exporters

Export invoices must be reported on the IRP with supply type EXPWP (export with payment of IGST) or EXPWOP (export without payment, under LUT). The e-invoice portal requires the shipping bill number and port code for export invoices. If the shipping bill is not yet available at the time of e-invoice generation, generate the e-invoice with available details and update the shipping bill reference in GSTR-1 during filing. Export e-invoices auto-populate GSTR-1 Table 6B and 6C.

Multi-Branch Businesses

Businesses with multiple GSTINs (branches in different states) must generate e-invoices separately for each GSTIN. Register each GSTIN on the e-invoice portal independently. For inter-branch stock transfers, if you issue a tax invoice for the transfer (treated as a supply under GST), it must be reported on the IRP. The supplying branch generates the e-invoice, and the receiving branch sees it in their GSTR-2A/2B for ITC claim.

E-Invoice Reporting Timeline and Restrictions

The government has imposed a time limit on reporting invoices on the IRP. Understanding this timeline prevents "invoice not reportable" errors.

Reporting Window

For businesses with aggregate turnover of ₹100 crore and above, the e-invoice reporting window is 30 days from the invoice date. Invoices older than 30 days cannot be reported on the IRP. For businesses with turnover between ₹5 crore and ₹100 crore, a wider reporting window applies (currently the current month plus the preceding month). This means if you issue an invoice on 1 March 2026, it must be reported on the IRP by 30 April 2026 at the latest. Always generate e-invoices on the same day as the invoice date or within 1 to 2 days to avoid last-minute failures or missed deadlines.

Financial Year Transition

During the March-April transition, ensure all March invoices are reported on the IRP before the reporting deadline. Invoices dated 31 March falling into the next financial year's reporting window can create complications. Our recommendation: generate e-invoices daily rather than in batches at month-end, especially during March when invoice volumes are typically highest.

Consequences of Missing the Reporting Window

If you miss the IRP reporting deadline, the invoice cannot be reported on the portal. You must issue a fresh invoice with the current date, cancel or reverse the original invoice in your books, and report the new invoice on the IRP within the permissible window. The original invoice number becomes void for e-invoicing purposes. This situation creates reconciliation challenges in GSTR-1 and affects the buyer's ITC claim timing. Businesses that generate e-invoices in real time (same day as invoice creation) avoid this risk entirely. Set up automated alerts in your accounting software to flag invoices pending IRP reporting beyond 48 hours of creation.

E-Invoice Format and Printing Requirements

The printed or shared e-invoice must contain specific elements mandated by the government to be considered valid. Missing any required element can lead to compliance issues during GST audits. Every e-invoice document shared with the buyer must display the Invoice Reference Number (IRN), the digitally signed QR code, and the acknowledgement number and date returned by the IRP. The QR code must be scannable and printed at a minimum resolution that allows QR reader apps to decode it. Include the IRN as alphanumeric text alongside the QR code for manual verification.

Mandatory Print Fields

• IRN: The 64-character Invoice Reference Number printed as text above or below the QR code
• QR Code: The digitally signed QR code returned by the IRP, printed clearly at minimum 2cm x 2cm size
• Acknowledgement Number: The IRP acknowledgement number for traceability
• Acknowledgement Date: The timestamp of IRP validation
• All standard GST invoice fields: Supplier/buyer GSTIN, HSN codes, tax breakup, as per Rule 46 of CGST Rules

Digital Sharing Considerations

When sharing e-invoices electronically (email PDF, WhatsApp, or through an e-invoicing platform), embed the QR code as an image within the PDF. The QR code must remain scannable after printing the PDF. Test the QR code readability by printing a sample invoice and scanning it with a mobile QR reader. Ensure your accounting software generates print-ready invoice templates that include the IRN and QR code fields automatically. Manual addition of these elements increases the risk of errors and omissions. Most compliant accounting packages like Tally Prime, Zoho Books, and Busy Accounting update the invoice template automatically after receiving the IRP response.

E-Invoice Record Keeping

Maintain proper records of all e-invoices for audit and compliance purposes.

What to Store

• IRN: The 64-character Invoice Reference Number for each e-invoice
• Acknowledgement number and date: Proof of IRP acceptance
• Signed QR code data: For buyer verification and audit trail
• Original JSON payload: The invoice data submitted to the IRP
• IRP response data: The complete signed response including digital signature
• Cancellation records: If any e-invoice was cancelled, store the cancellation acknowledgement

Retention Period

Under Section 36 of the CGST Act, every registered person must retain books of accounts and records for 72 months (6 years) from the due date of filing the annual return for that year. E-invoice data falls under this retention requirement. Store both electronic copies (in your accounting software and as backup files) and printed copies (if your internal audit policy requires physical records). For API users, implement automated archival of IRP responses to ensure long-term data availability.

Related Resources

• GST Registration Service: Register your business for GST before setting up e-invoicing
• GST Return Filing Service: Monthly GSTR-1 and GSTR-3B filing with e-invoice reconciliation
• Compliance Services: End-to-end GST compliance management for businesses
• Private Limited Company Compliance: Annual compliance including GST and e-invoicing for Pvt Ltd companies
• GST Calculator: Calculate GST liability on your transactions
• GSTR-1 vs GSTR-3B: Key Differences: Understand the relationship between GSTR-1 auto-population and GSTR-3B filing
• AI Tools for GST and ROC Compliance: How AI can simplify your e-invoicing and compliance workflow

Summary

E-invoicing is mandatory for GST-registered businesses with aggregate turnover exceeding ₹5 crore in any financial year since 2017-18. Generate e-invoices on the IRP at einvoice1.gst.gov.in by registering on the portal, preparing invoice data in the JSON schema, uploading to the IRP, and receiving the IRN and QR code. Choose from four generation modes: web portal, JSON upload, bulk Excel upload, or API integration based on your invoice volume. E-invoice data auto-populates GSTR-1 and Part A of the E-Way Bill, reducing manual compliance effort. Cancel within 24 hours on the IRP or use credit/debit notes after 24 hours. Non-compliance attracts ₹25,000 penalty per invoice. For professional GST compliance assistance, contact our team.