GST · 26 June 2026
What Is the Time of Supply Under GST, and When Does Tax Become Due?
The time of supply is the point at which GST becomes payable, fixed by Section 12 of the CGST Act for goods and Section 13 for services. It decides which tax period a supply belongs to, and so which GSTR-3B pays the tax. For goods, the time of supply is the date the invoice is issued, or the last date by which it should have been issued under Section 31; the payment trigger was removed by Notification 66/2017, so an advance for goods is not taxed early. For services, it is the earlier of the invoice date, provided the invoice is raised within 30 days under Rule 47, or the date of payment. Under the reverse charge mechanism, Section 12(3) and 13(3) shift the time of supply to the earlier of the payment date or the day after a fixed window from the supplier's invoice, 30 days for goods and 60 days for services.
By Mrs. Swapna Patel
Last reviewed
26 June 2026
In this section
Answers
- What Is the Time of Supply Under GST, and When Does Tax Become Due?
- What Is GSTR-1, the GST Return of Outward Supplies?
- What Is GSTR-3B, the Monthly GST Summary Return?
- Advance Receipt Under GST: When Do You Issue a Receipt Voucher?
- Credit Note vs Debit Note Under GST: When Do You Issue Each?
- What Is a Pakka Bill? The GST Invoice That Counts as Valid
- What Is a Kaccha Bill? Why the Rough Slip Has No GST Standing
- Why Move From a Kaccha Bill to a Pakka Bill?
- How to Upgrade From a Kaccha Bill to a Pakka Bill (GST Invoice)
- 5 GST Invoice Mistakes That Trigger a Tax Notice (And How to Fix Them)
GST becomes payable only when my customer actually pays me.
GST falls due at the time of supply, fixed by Section 12 for goods and Section 13 for services. For goods that is usually the invoice date, not the payment date, so tax can be due before the money arrives.
What is the time of supply in GST?
Short answer
The point at which GST becomes payable, set by Section 12 for goods and Section 13 for services. It decides which tax period, and so which GSTR-3B, pays the tax.
- It is about timing, not amount: it fixes when the liability arises, not how much.
- Get it wrong and a supply lands in the wrong month, understating one return and overstating another.
- Why it matters: the time of supply, not your bank statement, decides the month you owe the tax.
What is the time of supply for goods?
Short answer
The date the invoice is issued, or the last date it should have been issued under Section 31. The payment trigger was removed by Notification 66/2017, so an advance for goods is not taxed early.
- In practice the invoice date is the time of supply for goods.
- If you fail to issue the invoice on time, the statutory last date applies anyway, so a missing invoice does not defer the tax.
- Why it matters: for goods you can owe GST in the month you invoice, even though the customer pays later.
What is the time of supply for services?
Short answer
The earlier of the invoice date, if the invoice is raised within 30 days under Rule 47, or the date of payment, under Section 13.
| Scenario | Time of supply |
|---|---|
| Invoice raised within 30 days of the service | Earlier of the invoice date or the payment date |
| Invoice not raised within 30 days | Earlier of the date the service was provided or the payment date |
| Advance received for a service | The advance date (so GST is due on the advance) |
Source: Section 13, CGST Act and Rule 47. Unlike goods, a service advance is taxed when received; see advance receipts and the receipt voucher.
When is the time of supply under reverse charge?
Short answer
Under Section 12(3) and 13(3), it is the earlier of the payment date or the day after a fixed window from the supplier's invoice: 30 days for goods, 60 days for services.
The reverse charge mechanism makes the recipient pay the tax, so the timing rule is built around the recipient too. If you have not paid the supplier within the window, the tax still falls due the day after it closes, which stops a delayed payment from deferring the liability indefinitely. The reverse-charge windows are fixed by statute, but the underlying notified-supply list changes, so confirm the supply is on it before applying the rule.
References & related
Primary sources
- Section 12, Central Goods and Services Tax Act 2017 (time of supply of goods) — India CodeTime of supply for goods, including the reverse-charge rule in Section 12(3).
- Section 13, Central Goods and Services Tax Act 2017 (time of supply of services) — India CodeTime of supply for services, the invoice-or-payment test, and the reverse-charge rule in Section 13(3).
- Rule 47, Central Goods and Services Tax Rules 2017 (time limit for issuing an invoice) — CBICA service invoice must be issued within 30 days of supply, which anchors the time-of-supply test.
- Notification 66/2017-Central Tax, 15 November 2017 — CBICRemoves the advance-payment trigger for goods, so the time of supply for goods is effectively the invoice date.
Last reviewed: 26 June 2026