Taxation · Tax Invoice; Credit and Debit Notes

Tax Invoice under GST: Meaning, Contents and Time Limits

Updated 4 October 2026 · Fact-checked

A tax invoice is the document a registered taxable supplier issues under Section 31 of the CGST Act to show the supply and tax charged. For goods, issue it before or at the time of removal or delivery. For services, issue it within 30 days of supply (45 days for insurers, banks and financial institutions).

Understand Tax Invoice: Meaning, Contents and Time Limits

A tax invoice is the supplier's proof that a taxable supply took place and that GST was charged on it. The recipient uses it to claim input tax credit. The department uses it to trace the supply. So the law fixes who issues it, what it must show and when it must be issued.

Section 31 of the CGST Act says a registered person making a taxable supply must issue a tax invoice. A registered person who makes only exempt supplies, or who is under the composition scheme, issues a bill of supply instead and does not charge tax. A tax invoice is not for them.

The timing rule differs for goods and services. For goods, if the supply involves movement, the invoice is due before or at the time of removal. If there is no movement, it is due before or at the time of delivery or making the goods available to the recipient. For services, the invoice can be issued before or after the service, but within the prescribed period under Rule 47: 30 days from the date of supply. Insurers, banking companies and financial institutions (including NBFCs) get 45 days.

Special timing applies to continuous supply of services, supply that ceases before completion, and goods sent on approval. Rule 46 lists the particulars the invoice must carry. Rule 48 deals with the manner of issuing it, including the number of copies.

Key rules to remember

Time limit for goods (Section 31): Invoice date ≤ date of removal (goods that move); invoice date ≤ date of delivery or making available (goods that do not move); Issue it before or at the time. It cannot wait until after the goods leave.
Time limit for services (Rule 47): Last date = date of supply + 30 days; Insurer, banking company or financial institution including NBFC: date of supply + 45 days. The invoice may also be issued before the service.
Continuous supply of services: Due date of payment ascertainable from contract: on or before that due date. Not ascertainable: before or at the time of receiving payment. Payment linked to completion of an event: on or before completion of that event.; Three cases, each with its own trigger.
Continuous supply of goods: Invoice before or at the time each statement of accounts is issued or each payment is received; Applies where successive statements of accounts or successive payments are involved.
Supply ceasing before completion: Invoice at the time the supply ceases, to the extent of the supply made so far; Applies to services under a contract that ends early.
Goods sent on approval: Latest date for invoice = earlier of (date of supply, six months from date of removal); This is a deadline, not a fixed invoice date. The invoice may be issued earlier. It applies where goods are removed before it is known whether a supply will take place.
Mandatory particulars (Rule 46): Supplier name, address and GSTIN; unique serial number (maximum 16 characters); date; recipient details; HSN or SAC; description; quantity and unit (goods); total value; taxable value after discount; tax rate and amount (CGST, SGST/UTGST, IGST, cess); place of supply and state name for inter-State supply; reverse charge indication; signature; For a registered recipient, show name, address and GSTIN or UIN. For an unregistered recipient where the value of the taxable supply is ₹50,000 or more, show name, address, delivery address, and state name and code. Where the value is below ₹50,000, the unregistered recipient's details are required only if the recipient requests them.
Number of copies (Rule 48): Goods: triplicate (original for recipient, duplicate for transporter, triplicate for supplier). Services: duplicate (original for recipient, duplicate for supplier); These copy requirements apply to manual or non-e-invoice documents. Notified persons issue e-invoices with an invoice reference number (IRN) and QR code under Rule 48(4).

How to solve Tax Invoice: Meaning, Contents and Time Limits questions

Use this order for any question on tax invoice. It matches the provision, facts, conclusion format that earns step marks.

1Identify the supplier. Check whether the supplier is registered and whether it is a normal taxpayer, a composition dealer or an exempt supplier. Composition and exempt suppliers issue a bill of supply, not a tax invoice.
2Identify the supply as goods or services. This decides the timing rule.
3Pick the trigger. For goods, use removal (if movement) or delivery (if none). For services, use the date of supply plus 30 or 45 days. Check whether the facts match a special case: continuous supply, cessation, or goods on approval.
4Compute the last date by counting days carefully from the date of supply. Mind the month lengths.
5If the question asks for contents, list the Rule 46 particulars that apply on the facts. Check the recipient's registration status and the ₹50,000 limit, inter-State supply, and reverse charge.
6If copies are asked, give the count and the purpose of each copy: triplicate for goods, duplicate for services. Note that this applies to non-e-invoice documents.
7State the conclusion in one line, with the provision: Section 31 and Rules 46 to 48.

Quickest way: Goods or services, then trigger, then date

When to use it: Use it for MCQs and for short-answer parts. It gets the answer in under a minute.

MCQ: first ask whether it is goods or services. Eliminate any option that gives 30 days for goods, or 'at the time of removal' for services.
If the question mentions an insurer, bank or NBFC, jump to 45 days. Otherwise 30 days.
If the question mentions a bill of supply, check the supplier: composition or fully exempt.
For counting days, add days to the month-end first, then carry the rest into the next month.
Written answer: write the format Provision, Facts, Conclusion. Quote Section 31 and the Rule number. Show the date calculation in one line. Even a short answer scores step marks this way.

Common mistakes in Tax Invoice: Meaning, Contents and Time Limits

Applying 30 days to every service supplier.
Students remember '30 days' and forget the exception.
Fix: Attach the exception to the rule in your notes: insurers, banking companies and financial institutions including NBFCs get 45 days.
Saying a goods invoice may be issued within 30 days of supply.
The services rule gets applied to goods.
Fix: For goods, the invoice is due before or at the time of removal or delivery. There is no grace period.
Issuing a tax invoice for composition dealers or exempt supplies.
Students treat every invoice as a tax invoice.
Fix: Composition suppliers and suppliers of exempt goods or services issue a bill of supply. They do not charge tax.
Mixing up the copies for goods and services.
Both rules sound similar.
Fix: Goods: three copies (recipient, transporter, supplier). Services: two copies (recipient, supplier).
Listing recipient name and address as mandatory for every unregistered buyer.
Students ignore the value condition.
Fix: For an unregistered recipient, these details are mandatory when the value of the taxable supply is ₹50,000 or more. Below that, they are needed only if the recipient requests them. A registered recipient's GSTIN or UIN must always be shown.
Ignoring the special timing rules for continuous supply, early cessation and approval sales.
Students learn only the two main rules.
Fix: Read the facts for words like 'monthly statement', 'contract terminated', 'on approval' and use the matching rule.

Worked examples

Example 1

Sharma & Co., a registered firm of consultants, completes a taxable service for a client on 10 March 2027. (a) By what date must it issue the tax invoice? (b) Would your answer change if the supplier were an NBFC?

Show the solution

Provision: under Section 31 read with Rule 47, a registered person supplying taxable services must issue the tax invoice within 30 days from the date of supply of service. Financial institutions, including NBFCs, get 45 days.
Facts (a): date of supply is 10 March 2027. Add 30 days. Days left in March after the 10th: 21, which takes us to 31 March. Remaining days: 30 − 21 = 9. The date is 9 April 2027.
Facts (b): add 45 days. 21 days take us to 31 March. Remaining days: 45 − 21 = 24. The date is 24 April 2027.

Answer: (a) Sharma & Co. must issue the invoice by 9 April 2027. (b) An NBFC supplier would have until 24 April 2027.

Example 2

Ravi Traders, Pune, a registered dealer, removes goods on 12 January 2027 to a buyer in Delhi on approval for sale or return. The buyer approves the purchase on 20 May 2027. State the latest date for issuing the invoice. What if the buyer never approves?

Show the solution

Provision: where goods are removed on approval before it is known whether a supply will take place, the invoice must be issued before or at the time of supply, or within six months from the date of removal, whichever is earlier. Where the supply has not taken place within six months, the invoice is issued on expiry of six months from removal.
Facts: removal is on 12 January 2027. Six months from removal ends on 12 July 2027. Supply takes place on approval on 20 May 2027.
Compare: 20 May 2027 is earlier than 12 July 2027, so the invoice is due on or before 20 May 2027.
If the buyer never approves and no supply takes place within six months, the invoice is issued on expiry of six months from removal, that is by 12 July 2027.
Copies: since this is a supply of goods, a non-e-invoice document is prepared in triplicate. The original goes to the recipient, the duplicate to the transporter and the triplicate stays with the supplier. Because the supply is inter-State (Pune to Delhi), the invoice shows IGST and the place of supply with the state name. If the supplier is notified for e-invoicing, an e-invoice with IRN and QR code is issued instead.

Answer: The latest date is 20 May 2027, the earlier date. If no supply takes place within six months, the invoice is issued on expiry of six months from removal, i.e. by 12 July 2027. The invoice carries IGST, as the supply is inter-State.

Exam tips

Time-limit questions are easy marks. Memorise 30 days, 45 days and the special cases in a single list.
Always write the section and rule number in the answer. Use Section 31 for timing and Rules 46 to 48 for particulars, timing for services and copies.
In MCQs, watch for options that swap goods and services rules or copy counts.
In date problems, show the month-end carry step. A correct method earns marks even if the final date slips.
In a 'contents of invoice' question, list the particulars in a clear bullet order. Add conditions such as the ₹50,000 limit and inter-State supply.

Practice questions from Tax Invoice; Credit and Debit Notes

Tax Invoice: Meaning, Contents and Time Limits in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Tax Invoice: Meaning, Contents and Time Limits: frequently asked questions

Who must issue a tax invoice under Section 31?

A registered person making a taxable supply of goods or services must issue a tax invoice. A composition dealer or a supplier of exempt goods or services issues a bill of supply instead.

What is the time limit to issue a tax invoice for services?

The invoice must be issued within 30 days from the date of supply of service. For insurers, banking companies and financial institutions including NBFCs, the limit is 45 days.

Can a tax invoice be issued before the supply?

Yes. For services, the law lets you issue it before or after the service, within the prescribed period. For goods, it must be issued before or at the time of removal or delivery, so issuing earlier is allowed.

How many copies of a tax invoice are needed?

For goods, three copies: original for the recipient, duplicate for the transporter and triplicate for the supplier. For services, two copies: original for the recipient and duplicate for the supplier. This applies to non-e-invoice documents. Notified persons issue e-invoices with an IRN and QR code instead.

What is the maximum length of an invoice number?

Rule 46 allows a consecutive serial number of up to 16 characters. It may use letters, numbers, a hyphen or dash, and a slash. It must be unique for the financial year.