GST time of supply under sections 12 and 13
How the time of supply fixes when GST becomes payable: the earlier-of rule for goods under section 12 and services under section 13 of the CGST Act, and how reverse charge changes the trigger.
In this guide
Time of supply fixes the point at which GST becomes payable. For goods, section 12 of the CGST Act sets it as the earlier of the date of the invoice, or the last date by which the invoice should have been issued. For services, section 13 sets it as the earlier of the invoice date, or the date of receipt of payment, with fallback dates where an invoice is not issued in time. Under reverse charge the trigger shifts to the date of payment or receipt of goods or services, subject to the specific rules in each section.
What does time of supply decide?
Time of supply decides when the liability to pay GST arises. Section 12 sets it for goods and section 13 sets it for services.
Once the time of supply falls in a tax period, the tax on that supply belongs to that period's return. The rule is built around an earlier-of test, so the first of the listed events fixes the date.
What is the time of supply for goods?
For goods, the time of supply is the earlier of the date the supplier issues the invoice, or the last date by which the invoice should have been issued. The invoice for goods is generally due on or before removal or delivery.
So if the invoice is raised on time, its date is the time of supply. If it is late, the last permitted invoice date applies instead, which stops a delayed invoice from pushing the tax into a later period.
What is the time of supply for services?
For services, the time of supply is the earlier of the invoice date or the date of receipt of payment, provided the invoice is issued within the allowed period. The invoice for a service is generally due within 30 days of providing it.
If the invoice is not issued within that period, the time of supply is the earlier of the date the service is provided or the date payment is received. Unlike goods, an advance for a service triggers the time of supply on receipt.
How does reverse charge change it?
Under reverse charge, the recipient pays the tax, and the trigger moves away from the supplier's invoice. The rule differs for goods and services.
| Supply | Earliest of |
|---|---|
| Goods (reverse charge) | Receipt of goods, payment, or day after 30 days from invoice |
| Services (reverse charge) | Payment, or day after 60 days from invoice |
For who must pay under reverse charge in the first place, read our GST reverse charge guide.
What about advances received?
For a forward-charge supply of goods, GST is not payable on an advance under a notified relief, so the invoice-based rule governs. For services, an advance is different: the date payment is received becomes the time of supply for that amount.
This split means a business taking advances for services accounts for tax earlier than one taking advances for goods. The receipt date, not the later invoice, drives the service liability.
How do I apply the rule?
- Identify whether the supply is of goods or services.
- Check whether forward charge or reverse charge applies.
- For forward charge, run the earlier-of test in section 12 or 13.
- For reverse charge, use the payment or fixed-day trigger.
- Report the tax in the period the time of supply falls in.
Where do businesses go wrong?
- Treating a late invoice date as the time of supply for goods.
- Missing the payment-receipt trigger on service advances.
- Applying the goods reverse-charge days test to services.
- Ignoring the 30 or 60-day fallback under reverse charge.
- Reporting a supply in the wrong tax period.
Where are the timing rules published?
The timing rules sit in section 12 of the CGST Act for goods and section 13 for services, with the value in section 15. For the value side, read our GST value of supply guide. Complied AI keeps CBIC / GST updates in one feed so you can open a notification that changes an invoice period and read section 12 next to it.
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Common questions
What is time of supply under GST?
Time of supply is the point that fixes when the liability to pay GST arises. Section 12 of the CGST Act sets it for goods and section 13 sets it for services. Once the time of supply falls in a tax period, the tax on that supply is payable for that period.
What is the time of supply for goods?
Under section 12, the time of supply for goods is the earlier of the date the supplier issues the invoice, or the last date on which the invoice should have been issued. The invoice for goods must ordinarily be issued on or before the removal or delivery of the goods, so that last date sets the outer limit.
What is the time of supply for services?
Under section 13, the time of supply for services is the earlier of the invoice date or the date of receipt of payment, if the invoice is issued within the period allowed. If the invoice is not issued in time, it is the earlier of the date of provision of the service or the date of receipt of payment.
How does reverse charge change the time of supply?
Under reverse charge for goods, the time of supply is the earliest of the date of receipt of goods, the date of payment, or the day immediately after 30 days from the invoice date. For services under reverse charge, it is the earlier of the date of payment or the day immediately after 60 days from the invoice date.
Is GST payable on an advance received for goods?
For goods, GST is not payable on an advance for a normal forward-charge supply; the time of supply is tied to the invoice under a notified relief. For services, an advance does trigger the time of supply on the date the payment is received, so tax on a service advance is payable in that period.
What is the time of supply for a voucher?
For a voucher, the time of supply is the date of issue if the supply is identifiable at that point, and otherwise the date the voucher is redeemed. This special rule sits within sections 12 and 13, separate from the general earlier-of tests.
Which date counts as receipt of payment?
The date of receipt of payment is the earlier of the date the payment is entered in the supplier's books, or the date the amount is credited to the supplier's bank account. Whichever comes first is the date used when the earlier-of test looks at payment.
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How this guide was prepared
This guide is published by the Complied AI research desk. Its source list and stated position were checked against the official records shown below on 19 September 2026.
Automation, including AI, may assist research, drafting and structure. It does not replace the official record or amount to an independent professional review. Read our editorial standards and corrections policy.
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