Invoicing & Documents
The paperwork that makes a transaction real
The paperwork that makes a transaction valid.
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In GST, the invoice is not an accounting formality – it is the legal instrument that carries the tax and the credit. If the document is defective, the buyer’s credit fails, and the problem usually surfaces months later in their reconciliation rather than yours.
Which document you issue depends on what you are: a registered supplier making a taxable supply issues a tax invoice; a composition dealer or a supplier of exempt goods issues a bill of supply, which carries no tax and gives the buyer no credit. Getting this wrong is one of the fastest ways to lose a business customer.
Above ₹5 crore turnover in any year since GST began, B2B invoices must also be registered on the e-invoice portal and carry an IRN. Without the IRN the invoice is legally not an invoice at all – regardless of how correct everything else on it looks.
Worked example
A missing IRN, discovered four months later
| Supplier crosses ₹5 crore in March | E-invoicing now applies | Billing software never updated |
| Raises 300 B2B invoices over four months | All look perfectly normal | None carry an IRN |
| Buyer’s reconciliation flags them | Credit denied on all 300 | Penalty exposure: ₹10,000 per invoice |
Nothing about the invoices looked wrong. They were simply not invoices in law. This is the single most expensive silent failure in GST compliance.
The mistakes that cost people money
Not theoretical risks — the ones we actually see land on clients’ desks.
Missing the e-invoicing trigger because you only checked this year’s turnover. The test looks back at every financial year since 2017-18.
Issuing a tax invoice while registered under composition. You are not permitted to collect tax, and doing so puts your scheme eligibility at risk.
Issuing a credit note after the November cutoff. The commercial adjustment may still be possible, but the tax adjustment is time-barred.
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Invoicing & Documents — the complete guide
9 pages covering all 23 provisions, with the plain-language explanation and practice notes for each. Print it, keep it, share it with your accountant.
Common questions on this
Straight answers to what people actually ask us.
Time Limit for Issuing a GST Credit Note
A GST credit note must be declared by 30 November of the following financial year, or the annual return date —…
Is E-Invoice Compulsory for Your Business?
E-invoicing is mandatory once your turnover crosses ₹5 crore in ANY year since GST began — and it stays mandat…
What Happens If an Invoice Should Have Been E-Invoiced but Wasn’t?
An invoice that needed an IRN but doesn’t have one isn’t a valid tax invoice — meaning no ITC for the buyer, a…
Every provision on invoicing & documents
All 23 of them, each with a plain-language explanation and the full legal text.
CGST Rules, 2017 · 16
CGST Act, 2017 · 7
Reading is free. Getting it wrong isn’t.
Stuck on invoicing & documents for your own business?
You now know more about this than most people who will advise you on it. If the numbers are big enough that being wrong matters, send us the facts – we will tell you where you stand before you commit to anything.
6+ years · 2,500+ GST registrations filed · Bhopal, serving all of India