E-Invoice Limit in GST 2026: Turnover Threshold, Rules & Busy Setup

What is the e-invoice limit is one of the most searched GST questions in India, and for good reason: the threshold has been lowered repeatedly since e-invoicing began, pulling smaller and smaller businesses into scope with each phase. If your aggregate turnover crossed the notified limit in any financial year from 2017-18 onwards, e-invoicing is mandatory for you permanently, even if turnover later falls. This guide explains the current e-invoice limit, how to check whether you are covered, what happens if you ignore it, and how to generate compliant e-invoices from Busy Software without changing your billing routine.

What is an e-invoice under GST?

An e-invoice is not an invoice created on a government website. It is a normal invoice raised in your own accounting software, reported in a standard schema to the Invoice Registration Portal, and returned to you with a digitally signed Invoice Reference Number and a QR code. Only after that registration is the document treated as a valid tax invoice for GST purposes.

The design intent is straightforward: one authenticated source of invoice truth that flows automatically into GSTR-1 for the supplier, into GSTR-2B for the buyer, and into the e-way bill system for the transporter. That is why e-invoicing removes work rather than adding it once configured. Your outward supply data is pre-populated instead of re-typed.

The e-invoice turnover limit and how the threshold has moved

E-invoicing was rolled out in phases, each phase lowering the aggregate annual turnover threshold:

• October 2020, businesses with aggregate turnover above Rs 500 crore
• January 2021, above Rs 100 crore
• April 2021, above Rs 50 crore
• April 2022, above Rs 20 crore
• October 2022, above Rs 10 crore
• August 2023, above Rs 5 crore, which is the current mandate for most taxpayers

The operative test is aggregate turnover in any preceding financial year starting from 2017-18. This trips people up constantly. A business that touched Rs 6 crore in 2021-22 and has since settled at Rs 3 crore is still within the e-invoicing mandate. There is no exit once you are in.

Aggregate turnover is computed PAN-wide, not GSTIN-wide, and includes taxable supplies, exempt supplies, exports and inter-state supplies of persons with the same PAN. It excludes CGST, SGST, IGST and cess. Many businesses with several GSTINs under one PAN discover they are in scope only after adding the registrations together.

Who is exempt from e-invoicing?

Certain categories are excluded regardless of turnover. These currently include Special Economic Zone units, insurers, banking companies and financial institutions including NBFCs, goods transport agencies supplying road transport services, suppliers of passenger transportation services, suppliers of services by way of admission to cinematograph film exhibitions in multiplex screens, and government departments and local authorities. Business-to-consumer invoices are also outside the e-invoice requirement, though larger taxpayers must print a dynamic QR code on B2C invoices, which is a separate obligation often confused with e-invoicing.

Which documents need an IRN?

If you are covered, IRN generation applies to B2B tax invoices, invoices to SEZ units and developers, exports with or without payment of tax, deemed exports, credit notes and debit notes. Delivery challans, bills of supply for exempt goods, financial credit notes and B2C invoices do not require an IRN.

The 30-day reporting rule

Time limits now apply to reporting. Taxpayers above the notified turnover threshold must report invoices to the portal within 30 days of the document date, and the portal blocks registration of older documents. An unreported invoice past the window cannot be regularised, and the buyer cannot claim input tax credit on a document with no valid IRN. This is a strong argument for generating the IRN at the moment of billing rather than in a month-end batch.

Consequences of not generating an e-invoice

• An invoice without a valid IRN is not a valid tax invoice, so legally it is as if you did not issue one.
• Your customer loses input tax credit, which quickly becomes a commercial problem rather than only a tax one.
• Penalty for non-issuance is Rs 10,000 or the tax involved, whichever is higher, per invoice.
• Penalty for an incorrect e-invoice is Rs 25,000 per invoice.
• Goods moved against a non-compliant invoice risk detention alongside e-way bill scrutiny.

How to generate e-invoices in Busy Software

Busy Software has native Invoice Registration Portal integration, so an e-invoice is a by-product of saving a sales voucher rather than a separate chore. The setup is one-time.

Setting up

• Register on the e-invoice portal and create API credentials for your GSP.
• In Busy, enable e-invoicing under Administration, Configuration, Features and Options, GST and VAT.
• Enter your API username, password and client credentials in the e-invoice configuration screen.
• Verify that every B2B party master has a valid GSTIN, state code, address and PIN, and that every item master has an HSN code and a unit mapped to the GST UQC list.

Day-to-day billing

• Raise the sales invoice normally.
• On save, Busy transmits the schema to the portal and receives the IRN, acknowledgement number and signed QR code.
• The QR code and IRN print on the invoice automatically using your existing invoice format.
• If transport details are filled in, Busy can request the e-way bill in the same call, so one action completes two compliances.
• Failed transmissions land in a pending report with the exact portal error message so you can correct and retransmit.

Cancellation follows the portal rule. An IRN can be cancelled within 24 hours of generation, in full only, because partial cancellation is not permitted. After 24 hours, issue a credit note instead. Busy records the cancellation against the voucher so your returns stay consistent.

How e-invoicing changes your GSTR-1 workflow

Once IRNs are flowing, your B2B outward supplies auto-populate in GSTR-1. The filing job shifts from data entry to reconciliation: confirm that every invoice in your books has an IRN, that no cancelled IRN is still sitting in the return, and that B2C and exempt supplies, which do not auto-populate, are added manually. Busy's e-invoice register gives you that reconciliation view directly, listing invoices with an IRN, without an IRN and cancelled, for any date range.

Preparing before the threshold drops again

The direction of travel is clear. Each phase has lowered the limit, and further reduction toward smaller taxpayers is widely anticipated. If your turnover is between Rs 2 crore and Rs 5 crore, the sensible move is to get masters clean now: correct HSN codes on every item, validated GSTINs on every party, UQC-mapped units, and a billing process that captures address and transport detail at entry. Businesses that do this find the eventual switch takes an afternoon. Businesses that do not spend weeks cleaning data under deadline pressure.

For the wider picture on invoicing, returns and compliance workflow, see our GST billing software guide and the GST billing software page.