Indirect Tax Laws · Time of Supply

Time of Supply of Goods under Reverse Charge (Section 12(3) CGST Act)

Updated 5 October 2026 · Fact-checked

Under reverse charge, the time of supply of goods is the earliest of three dates: the date you receive the goods, the date of payment (books entry or bank debit, whichever is earlier), or the date immediately after 30 days from the supplier's invoice. If none can be fixed, use the date of entry in your books.

Understand Time of Supply of Goods under Reverse Charge

Time of supply decides the moment GST becomes payable. It fixes the tax period in which you must report the supply and pay tax. The rate and value are also tested as on this date.

In normal (forward) charge, the supplier pays the tax, so the rule looks at the supplier's invoice and payment received. In reverse charge, the recipient pays the tax. So the law looks at events on the recipient's side: when the goods arrive, when the recipient pays, and how long the supplier's invoice has been outstanding.

Section 12(3) of the CGST Act gives three events. The time of supply is the earliest of them. The law does not wait for all three to happen. Whichever date comes first fixes the time of supply, and the later dates do not matter.

The third event is a safety net. It stops a recipient from delaying the liability by not paying or by delaying receipt. Once 30 days have passed from the supplier's invoice, the very next day becomes the time of supply, even if the goods have not arrived and nothing is paid.

The proviso gives a fallback. If you cannot determine the time of supply under any of the three events, it is the date of entry of the supply in the recipient's books of account.

Key rules to remember

Time of supply under reverse charge (goods): Time of supply = earliest of (A) date of receipt of goods, (B) date of payment, (C) date immediately following 30 days from the date of supplier's invoice; Applies where tax is paid or liable to be paid on reverse charge basis. The earliest date wins.
Date of payment (limb B): Date of payment = earlier of (date of entry in recipient's books of account, date of debit in recipient's bank account); Take the earlier of the two dates. Do not use the later one.
30-day date (limb C): Limb C date = invoice date + 31 days; The invoice day is not counted. Days 1 to 30 run after it, and the next day is the time of supply. Example: invoice 10 Sept gives 11 Oct.
Fallback rule: If time cannot be determined under A, B or C: time of supply = date of entry in recipient's books of account; This is the proviso to Section 12(3). It is used only when the three events cannot be applied.

How to solve Time of Supply of Goods under Reverse Charge questions

Use the same sequence every time. Write all dates in a small list first, then pick the earliest.

1Confirm the supply is a supply of goods on which tax is payable by the recipient under reverse charge. If it is forward charge, this rule does not apply.
2Note the date of receipt of goods (limb A).
3Find the payment date (limb B). If both a books entry date and a bank debit date are given, take the earlier. If there is no payment yet, limb B does not exist.
4Find the supplier's invoice date and compute the date immediately following 30 days: invoice date + 31 days (limb C). If no invoice has been issued, limb C does not arise.
5List the dates available and pick the earliest. That is the time of supply.
6If none of the three can be determined, take the date of entry in the recipient's books of account.
7State the conclusion in a line: the tax period in which the recipient must pay GST under reverse charge, and the rate of tax applicable on that date.

Quickest way: Three-date shortlist

When to use it: Use in MCQs and short case scenarios where dates are given and you need only the final date.

Write A = goods receipt, B = earlier of books or bank payment, C = invoice date + 31 days.
Cross out any limb for which no date is given.
Circle the smallest date. That is the answer.
Check the month-end carefully when adding 31 days. Add the days left in the invoice month first, then the balance.

Common mistakes in Time of Supply of Goods under Reverse Charge

Treating the supplier's invoice date as the time of supply.
Students carry over the forward charge habit of looking at the invoice first.
Fix: The invoice date matters only to compute limb C, which is the day after 30 days. The invoice date itself is not a time of supply.
Taking the 30th day, or the invoice date plus 30 days, as limb C.
The words 'immediately following thirty days' are read loosely.
Fix: Limb C is the day after the 30 days end, which is invoice date + 31 days. Invoice 10 Sept gives 11 Oct.
Using the later of the books entry and the bank debit as the payment date.
Students think payment is complete only when money leaves the bank.
Fix: The law says whichever is earlier of the books entry date and the bank debit date.
Waiting for all three events to happen before fixing the time of supply.
Students read 'earliest of' as 'after all of'.
Fix: The first of the three dates to occur fixes the time of supply. Later events are ignored.
Applying the books-entry fallback in every question.
It looks simple, so students use it as a shortcut.
Fix: The fallback applies only when the time cannot be determined under limbs A, B and C. If any of them can be determined, use the earliest.
Using the forward charge rule of Section 12(2) for a reverse charge purchase.
Students do not check who is liable to pay the tax.
Fix: First ask who pays the tax. If the recipient pays, apply Section 12(3). If the supplier pays, apply the forward charge rule.

Worked examples

Example 1

Alpha Ltd, a registered person, buys a notified class of goods on which GST is payable by the recipient under reverse charge. The supplier issues the invoice on 5 March 2026. Alpha receives the goods on 20 March 2026. Alpha records the payment in its books on 10 April 2026, and the bank debit is on 12 April 2026. Find the time of supply.

Show the solution

The supply is of goods under reverse charge, so Section 12(3) applies.
Limb A, receipt of goods: 20 March 2026.
Limb B, payment: earlier of 10 April (books) and 12 April (bank) is 10 April 2026.
Limb C: invoice date 5 March + 31 days. March has 26 days left after 5 March, so 5 March + 26 = 31 March. The remaining 5 days take us to 5 April 2026.
Dates: 20 March, 10 April, 5 April. The earliest is 20 March 2026.

Answer: The time of supply is 20 March 2026, the date of receipt of goods. Alpha Ltd must account for reverse charge GST in the tax period containing that date.

Example 2

Beta Traders buys goods on which it must pay GST under reverse charge. The supplier's invoice is dated 10 September 2026. The goods reach Beta on 15 October 2026. Beta enters the payment in its books on 25 October 2026, and the amount is debited in its bank account on 30 October 2026. Determine the time of supply.

Show the solution

Reverse charge on goods, so Section 12(3) applies.
Limb A, receipt of goods: 15 October 2026.
Limb B, payment: earlier of 25 October (books) and 30 October (bank) is 25 October 2026.
Limb C: invoice date 10 September + 31 days. September has 20 days left after the 10th, so 10 Sept + 20 = 30 Sept. The remaining 11 days take us to 11 October 2026.
Dates: 15 October, 25 October, 11 October. The earliest is 11 October 2026.
Receipt and payment both come after the 30-day limit, so limb C fixes the time of supply.

Answer: The time of supply is 11 October 2026, the day immediately following 30 days from the invoice date. Beta must pay reverse charge GST for the tax period that includes 11 October 2026.

Exam tips

Draw a small timeline of the three dates before answering. It saves time and shows the examiner your method.
Always compute limb C as invoice date + 31 days and show the working line, because marks are given for the date calculation.
In written answers, use provision-facts-conclusion form: state Section 12(3), apply the dates, then conclude the time of supply.
Watch for traps in case scenarios: an invoice not yet issued, two payment dates given, or goods received after the 30-day mark.
Check the first line of the question to see whether tax is payable on reverse charge. If it is not, answer under the forward charge rule.

Practice questions from Time of Supply

Time of Supply of Goods under Reverse Charge in other exams

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

Time of Supply of Goods under Reverse Charge: frequently asked questions

Which section of the CGST Act deals with time of supply of goods under reverse charge?

Section 12(3) of the CGST Act deals with it. It applies where tax is paid or liable to be paid on reverse charge basis. The time of supply is the earliest of three dates, with a fallback to the books entry date.

How do I calculate the date after 30 days from the invoice?

Add 31 days to the supplier's invoice date. The invoice day is not counted, so the 30 days run after it and the next day is the time of supply. An invoice dated 10 September gives 11 October.

What if the supplier has not issued an invoice?

Then limb C cannot be applied. You take the earlier of the goods receipt date and the payment date. If neither can be determined, the time of supply is the date of entry in your books of account.

Which payment date do I take if the books entry and the bank debit differ?

Take the earlier of the two. The law treats the earlier of the date of entry in the recipient's books and the date of debit in the bank account as the date of payment.