e-Invoicing in GST: Registration and IRN Guide

E-invoicing under GST requires notified businesses to report their B2B invoices to the government’s Invoice Registration Portal (IRP) before issuing them to customers. The portal validates each document, assigns a unique Invoice Reference Number (IRN) and returns a digitally signed invoice with a QR code. This guide explains, current as of 2026, who must comply, how enablement works, how to register and log in on einvoice1.gst.gov.in, and how to generate an IRN.

What is e-invoicing and who must comply

E-invoicing does not mean generating an invoice on a government website. You continue to raise invoices in your own accounting or billing software, but the invoice details must be reported to the IRP in a prescribed JSON schema. Only after the IRP authenticates the data and returns an IRN and QR code does the document become a valid tax invoice under GST law.

As of 2026, e-invoicing is mandatory for every GST-registered business whose aggregate annual turnover (AATO) has crossed Rs. 5 crore in any financial year since 2017-18. This Rs. 5 crore threshold has been in force since 1 August 2023 and remains the current applicable limit. Once you cross the threshold in any year, the obligation applies from the beginning of the next financial year and continues thereafter, even if turnover later falls.

The requirement applies to B2B supplies, supplies to SEZ units, exports, and to credit and debit notes relating to these. It does not apply to B2C invoices, though large taxpayers must display a self-generated QR code on B2C invoices separately.

Who is exempt

Certain categories are excluded regardless of turnover. These include banks and notified financial institutions, insurers, goods transport agencies, passenger transport operators, suppliers of admission to cinematograph film exhibitions in multiplexes, and SEZ units (as distinct from SEZ developers). Government departments and local authorities are also outside the framework.

How to check e-invoice enablement

The GST system automatically enables eligible taxpayers on the e-invoice portal based on turnover reported in returns. Before you attempt registration, confirm your status.

1. Visit einvoice1.gst.gov.in.
2. Open the “Search” menu and select “e-Invoice Status of Taxpayer” (the enablement status option).
3. Enter your GSTIN and the captcha, then submit.
4. The portal will display whether e-invoicing is enabled for that GSTIN.

Enablement is an eligibility flag, not a confirmation that your turnover has crossed the threshold. If your business is liable but not yet enabled, you can request enablement through the self-enablement option on the portal. Conversely, if you are shown as enabled but are genuinely exempt or below the limit, you are not required to generate IRNs simply because the flag is on. Assess your actual liability against the law.

How to register on the e-invoice portal

If you already use the e-way bill portal, your existing credentials work on the e-invoice portal and no fresh registration is needed. First-time users should register as follows.

1. Go to einvoice1.gst.gov.in and select “Registration”, then “Portal Login” or “e-Invoice Enablement”.
2. Enter your GSTIN and the captcha, then click “Go”.
3. The system auto-populates your applicant name, trade name, registered address, mobile number and email from GST records. Verify these details; if anything is wrong, correct it on the main GST portal first, as the e-invoice portal draws from the same database.
4. Click “Send OTP”. Enter the one-time password sent to your registered mobile number and email to authenticate.
5. Create a username and password of your choice for future access. Keep these credentials secure.

Once registered, you can also create sub-users for staff and register the GSTINs of transporters or API access if you integrate directly. If you forget your login details later, use the “Forgot Password” or “Forgot Username” option with your GSTIN and registered mobile number.

Logging in and two-factor authentication

To log in, enter your username, password and the captcha, then click “Login”. Two-factor authentication is in force on the portal: after entering your credentials you must also enter an OTP delivered to your registered mobile, email or through the NIC-GST-Shield or Sandes app. This applies to businesses across turnover slabs, so ensure your registered contact details are current.

Generating an IRN and QR code

The IRN is generated by the IRP, not typed by you. In practice most businesses generate IRNs automatically through their accounting software or a GST Suvidha Provider via API, so the invoice, IRN and QR code are produced in one workflow. The portal also allows manual and bulk generation.

1. Log in to einvoice1.gst.gov.in.
2. For a single invoice, prepare the invoice details in the prescribed format. For manual entry, use “e-Invoice” and then “Generate”, filling supplier, recipient, item and tax fields.
3. For volume, prepare a JSON file in the portal’s schema and go to “e-Invoice”, then “Bulk Upload”, and upload the file.
4. The IRP validates the data against GST rules, checks for duplicates and confirms the GSTINs.
5. On successful validation the portal returns a unique 64-character IRN, a digitally signed invoice, and a QR code.

Print the QR code and IRN on the invoice you issue to the buyer. The QR code carries key details such as the supplier and recipient GSTINs, invoice number, value, and the IRN, allowing quick authentication. An invoice in a notified category that does not carry a valid IRN is not treated as a valid tax invoice, which can affect your buyer’s input tax credit.

The 30-day reporting time limit

Businesses with an AATO of Rs. 10 crore and above must report invoices to the IRP within 30 days of the invoice date. This time limit, effective from 1 April 2025, means an IRN cannot be generated for documents older than 30 days. Reporting promptly rather than at month-end is therefore advisable for larger taxpayers.

Relationship with the GST portal

The e-invoice portal is a reporting layer that feeds the main GST system. Once an IRN is generated, the invoice data flows automatically into your GSTR-1 and into the e-way bill system where applicable, reducing duplicate data entry. This does not remove your return obligations; you must still review the auto-populated data and complete your GST return filing accurately each period. E-invoicing and returns are complementary, and reconciling IRN data against your books before filing helps avoid mismatches and notices.

Frequently asked questions

Is e-invoicing the same as filing a GST return?

No. E-invoicing is the real-time reporting of individual invoices to the IRP as they are raised, while GST returns are periodic summaries filed monthly or quarterly. E-invoice data auto-populates your GSTR-1, but you must still verify and file the return.

What is the current turnover limit for e-invoicing in 2026?

The threshold is an aggregate annual turnover of Rs. 5 crore, applicable since 1 August 2023 and unchanged as of 2026. Turnover of any financial year from 2017-18 onward is considered.

Can I cancel an IRN if I make a mistake?

An IRN can be cancelled on the portal within 24 hours of generation, and it must be cancelled in full, not amended. After 24 hours you cannot cancel it on the IRP and must make corrections through credit or debit notes and amendments in your GST return.

Do I need separate software to generate e-invoices?

Not necessarily. Small volumes can be handled manually or by bulk JSON upload on the portal. Most businesses, however, integrate their billing software or use a GST Suvidha Provider so that IRNs are generated automatically at the point of invoicing.

Managing enablement, IRN generation, the 30-day limit and reconciliation with returns can be demanding as your business grows. TAXAJ assists firms with end-to-end GST return filing and e-invoicing compliance so your reporting stays accurate and on time. Reach out to our team for tailored support.