GST Time of Supply – Sections 12, 13 & 14 Complete Practical Guide

Quick Answer: Which Date Determines GST?

Time of supply is the statutory point at which GST liability arises. It is not always the date on the invoice, and it is not always the date of payment.

Normal goods: Section 12 generally uses the earlier of the invoice date/last permissible invoice date and payment date, subject to its specific provisions.

Normal services: Section 13 generally uses the prescribed invoice/payment test, with different rules where the invoice is not issued within the prescribed period.

RCM: separate time-of-supply rules apply, and the recipient's payment/books can become decisive.

Rate change: Section 14 overrides Sections 12/13 and uses a matrix based on supply, invoice and payment occurring before or after the rate change.

Do not assume: “invoice date = GST liability date” for every transaction. RCM, continuous supply, associated enterprises and rate changes can produce different results.

1. Legal Framework – Sections 12, 13 & 14

Provision	Subject	Core purpose
Section 12	Time of supply of goods	Determines when GST on goods becomes payable.
Section 13	Time of supply of services	Determines when GST on services becomes payable.
Section 14	Change in rate of tax	Special matrix where the GST rate changes around the supply/invoice/payment dates.
Section 31	Tax invoice timing	Important because Sections 12/13 refer to the invoice or the time by which it is required to be issued.
Section 15	Value of supply	Determines the taxable value once time of supply is identified.

Current-law update: CBIC's current Section 12 text shows that the earlier voucher-specific provision in Section 12(4) was omitted with effect from 1 October 2025 by the Finance (No. 7) Act, 2025. citeturn0search2

2. Time of Supply of Goods – Section 12

2.1 Normal Forward-Charge Goods

For ordinary taxable goods, Section 12(2) generally uses the earlier of the date of issue of invoice/last date on which invoice is required to be issued and the date on which the supplier receives payment. citeturn0search1turn0search2

Invoice / payment	Time of supply – normal goods
Invoice first, payment later	Invoice/last permissible invoice date, as applicable.
Payment first, invoice later	Payment date, subject to the statutory rule.
Invoice and payment same date	That date.

2.2 Date of Receipt of Payment

Section 12 explains that the date of receipt of payment is the earlier of the date on which payment is entered in the supplier's books or the date on which it is credited to the supplier's bank account. citeturn0search1

2.3 Excess Payment up to ₹1,000

Section 12 contains a specific option for an amount received up to ₹1,000 in excess of the amount shown in the tax invoice, allowing the supplier to treat the invoice date as the time of supply for that excess amount.

2.4 Interest, Late Fee and Penalty

For an addition to the value of supply by way of interest, late fee or penalty for delayed payment of consideration, Section 12(6) places the time of supply on the date the supplier receives that addition in value. citeturn0search1

3. Time of Supply of Services – Section 13

Services require a different timing framework because invoice timing and the statutory invoice period are central to Section 13.

3.1 Where Invoice Is Issued Within the Prescribed Period

For the ordinary forward-charge service rule, time of supply is generally the earlier of the date of issue of invoice and receipt of payment.

3.2 Where Invoice Is Not Issued Within the Prescribed Period

Where the invoice is not issued within the prescribed period, Section 13 shifts the test to the date of provision of service or receipt of payment, as applicable. Therefore, delayed invoicing can create an earlier GST liability than the eventual invoice date.

3.3 Date of Receipt of Payment

For Section 13 purposes, payment is generally tested by the date it is entered in the supplier's books or credited to the bank account, whichever is earlier, subject to the statutory wording.

Important for contractors: payment terms do not automatically postpone GST liability. CBIC's sectoral FAQ explains that where services have been supplied and the statutory time-of-supply rule has been reached, GST can become payable even when the client has not yet released the money. citeturn0search3

3.4 Associated Enterprise – Cross-Border Service Supplier

For specified supplies of services by an associated enterprise where the supplier is located outside India, Section 13 contains a special rule using the earlier of the recipient's book-entry date and payment date.

4. Reverse Charge – Time of Supply Is Different

RCM requires a separate analysis because the person paying GST is the recipient rather than the ordinary supplier.

4.1 RCM Goods

Section 12(3) uses the earliest of the date of receipt of goods, the payment date under the statutory book/bank test, and the date immediately following 30 days from the supplier's invoice/document date. If the time cannot otherwise be determined, the recipient's book-entry date becomes relevant. citeturn0search1turn0search2

4.2 RCM Services

Section 13(3) generally uses the earlier of the recipient's payment date and the date immediately following 60 days from the supplier's invoice/document date. If neither can determine the time, the recipient's book-entry date applies. For specified foreign associated-enterprise services, a special earlier-of-books/payment rule applies. citeturn0search1

RCM supply	Key timing trigger
Goods	Receipt of goods / payment / 30-day invoice rule, whichever is earliest under Section 12(3).
Services	Payment / 60-day invoice rule, whichever is earlier under Section 13(3).
Foreign associated enterprise services	Recipient books/payment special rule.

5. Continuous Supply – Milestones Matter

5.1 Continuous Supply of Goods

Where goods are supplied continuously and involve periodic statements of accounts or successive payments, Section 31's invoice provisions and Section 12 timing must be read together. The contractual milestone and payment arrangement should be mapped to the tax invoice requirement.

5.2 Continuous Supply of Services

For continuous services, the point at which payment becomes due under the contract, the invoice date and the event specified in the contract can affect time of supply. The finance team should maintain a milestone calendar rather than waiting for bank payment.

Government works example: Departmental engineers certify a measurement book after work is completed. CBIC's FAQ notes that the service provider's invoice timing and the prescribed Section 13 rules determine the point of taxation; delayed payment by the government does not automatically postpone GST. citeturn0search3

6. Advances, Payment and Accounting Entries

6.1 Advance for Goods

For ordinary goods, the current Section 12(2) framework should be applied carefully rather than importing the old pre-GST practice or assuming every advance creates the same result as an advance for services. The exact supply and statutory provision should be documented.

6.2 Advance for Services

For services, receipt of advance/payment can become a time-of-supply event under the applicable Section 13 rule. Finance teams should therefore reconcile customer advances with GST liability rather than treating the advance as a pure balance-sheet item in every case.

6.3 Payment Date – Books vs Bank

When the Act uses the payment date, the statutory definition can make the earlier of book entry and bank credit relevant. The date shown by a bank statement alone should not automatically be used without checking the statutory explanation.

7. Special Situations

Interest on delayed payment
GST on the additional amount follows the specific time-of-supply rule when the supplier receives the interest/late fee/penalty.

Year-end accrual
Accounting provision does not automatically equal GST time of supply. Check whether a supply has occurred and which statutory trigger applies.

Unbilled services
Service completion and invoice timing can create GST liability before the invoice is booked.

RA bills
Map certification/milestones, invoice date and payment separately.

Mobilisation advance
Determine whether the amount is an advance against taxable service and apply the current time-of-supply provisions.

Retention money
Retention does not automatically decide time of supply; examine the contractual milestone and invoice rules.

Foreign service import
RCM time-of-supply rules can apply to imported services; payment and the 60-day invoice rule are important.

Related-party service
Associated-enterprise provisions can override the ordinary timing framework.

Vouchers
The earlier voucher-specific provisions in Sections 12/13 were changed by Finance (No. 7) Act, 2025; verify the current treatment rather than using old GST articles.

Price escalation
Determine whether the additional amount is a new supply, additional consideration or a separate statutory event.

8. Change in GST Rate – Section 14

Section 14 overrides the ordinary Section 12/13 rules when there is a change in the rate of tax. It examines whether the supply occurred before or after the rate change and whether invoice and payment occurred before or after it. citeturn1search0

8.1 The Three Dates

Date of supplyDate of invoiceDate of paymentRate-change date

Supply timing	Invoice	Payment	Section 14 result
Before rate change	After	After	Earlier of invoice/payment.
Before rate change	Before	After	Invoice date.
Before rate change	After	Before	Payment date.
After rate change	Before	After	Payment date.
After rate change	Before	Before	Earlier of invoice/payment.
After rate change	After	Before	Invoice date.

Four-working-day proviso: Section 14 contains a special rule for determining the date of receipt of payment where bank credit occurs after four working days from the rate-change date. citeturn1search0

Example

Suppose a service is supplied before a rate change. The invoice is issued after the rate change and payment is received before the rate change. Section 14's specific matrix can make the payment date the time of supply, meaning the earlier rate may apply depending on the complete statutory facts.

9. Construction, EPC, Mining, AMC & Year-End Projects

Situation	Time-of-supply control
RA bill certified in March, paid in May	Do not wait for May automatically; determine service invoice/time-of-supply rules.
Work completed but invoice delayed	Check Section 13 and Section 31; delayed invoicing can create earlier liability.
Retention released after defect period	Do not equate retention release date with the entire service's time of supply without analysing the contract.
Mobilisation advance	Track separately from final invoice and apply current advance/payment provisions.
Annual AMC	Determine whether it is a continuous service and identify invoice/payment/milestone events.
Electricity/utilities	Identify whether the transaction is taxable supply and determine the applicable timing provision.
Imported consultancy	Review RCM time-of-supply rules, especially the 60-day invoice test.
Foreign related-party service	Check the associated-enterprise rule under Section 13.

Year-end warning: an expense provision dated 31 March does not, by itself, prove that GST became payable on 31 March. The actual supply, invoice requirement, payment and applicable statutory section must be analysed.

10. GSTR-1, GSTR-3B & Month-End Controls

Once time of supply is determined, the finance team should ensure that the tax is reported in the correct return period. The accounting period and GST tax period are not necessarily identical when invoices, payments or RCM events cross month-end.

Supply eventTime of supplyTaxable valueGST rateInvoiceGSTR-1GSTR-3BReconciliation

Month-end question	Control
Was service supplied before month-end?	Check Section 13 even if invoice/payment is pending.
Was advance received?	Check goods/services distinction and applicable rule.
Is RCM applicable?	Apply recipient-side time-of-supply rule.
Did GST rate change?	Apply Section 14 matrix.
Is invoice delayed?	Check statutory invoice period and time of supply.
Is the amount only a provision?	Do not book GST merely from the accounting provision; first establish the statutory trigger.

11. 36 Practical Time-of-Supply Cases

#	Scenario	Core treatment
1	Goods invoice 10 April, payment 20 April	Normal goods: earlier relevant date under Section 12.
2	Goods payment 5 April, invoice 15 April	Payment can trigger earlier time of supply under the normal rule.
3	Service invoice 10 April, payment 20 April	Normal service rule generally uses earlier invoice/payment.
4	Service supplied, invoice issued late	Apply Section 13 late-invoice rule; liability may arise before invoice date.
5	Government contractor bill paid after 3 months	Payment delay does not automatically defer GST liability.
6	RCM goods received before invoice	Receipt date can become the time of supply.
7	RCM goods invoice old, payment later	Apply 30-day test and compare all statutory dates.
8	RCM service payment before 60 days	Payment date can trigger earlier liability.
9	RCM service invoice 1 January, no payment	Test the date immediately following 60 days.
10	Foreign related-party service booked before payment	Apply special associated-enterprise rule.
11	Customer advance for service	Check Section 13 payment/advance treatment.
12	Customer advance for goods	Apply current Section 12 goods provisions rather than assuming service treatment.
13	Interest received on delayed customer payment	GST time of supply for the additional value is linked to receipt of that addition.
14	March service invoice raised in April	Check statutory invoice timing and Section 13.
15	March RA bill certified in April	Identify the actual service/invoice event and applicable continuous-service rule.
16	Retention released after defect period	Retention release is not automatically the original service time-of-supply date.
17	Rate increases 1 July; supply before 1 July	Apply Section 14 based on invoice/payment timing.
18	Rate decreases 1 July; invoice before, payment after	Use Section 14 matrix.
19	Supply before rate change, invoice after, payment before	Payment date can determine time under Section 14.
20	Supply after rate change, invoice before, payment after	Payment date can determine time under Section 14.
21	Supply after rate change, invoice after, payment before	Invoice date can determine time under Section 14.
22	Bank credit occurs more than four working days after rate change	Apply Section 14's payment-date proviso.
23	Annual AMC invoiced upfront	Analyse service timing, continuous supply and invoice/payment rules.
24	Monthly SaaS subscription	Identify recurring/continuous service and invoice/payment timing.
25	Annual software licence	Determine actual supply and invoice/payment terms.
26	Mining contractor measured monthly	Map measurement/certification, invoice and Section 13.
27	Construction work completed but invoice pending	Accounting delay does not necessarily delay GST liability.
28	Year-end legal-fee provision	Provision alone does not determine GST time of supply.
29	Year-end audit-fee provision	Check actual service and invoice/payment timing.
30	Import of consultancy services	Apply RCM service time-of-supply rules.
31	Foreign group company charges management fee	Check associated enterprise rule and RCM.
32	Price escalation approved later	Identify when additional consideration becomes taxable under the actual supply arrangement.
33	Late-payment penalty charged to customer	Apply the specific interest/late-fee/penalty time rule if it forms part of value.
34	Voucher issued after 1 October 2025	Do not rely on the old Section 12(4) voucher timing rule; it was omitted effective 1 October 2025.
35	Invoice entered in books but bank credit later	Check statutory definition of payment date.
36	Invoice and payment straddle FY-end	Determine time of supply first; financial year accounting alone does not decide GST liability.

12. Accounting Entries – Practical Examples

Forward-Charge Service Invoiced Before Payment

Particulars	Debit (₹)	Credit (₹)
Customer Receivable	1,18,000	—
To Service Revenue	—	1,00,000
To Output GST	—	18,000

RCM Service Liability

Particulars	Debit (₹)	Credit (₹)
RCM Expense / Relevant Account	1,00,000	—
To Supplier / Accrued Liability	—	1,00,000
Input CGST/SGST or IGST, where eligible	18,000	—
To RCM GST Payable	—	18,000

Important: The accounting entry should follow the actual GST liability determined under the applicable time-of-supply provision. Do not create an RCM liability merely because an expense provision exists if the statutory time-of-supply event has not occurred.

13. GST Audit Questions on Time of Supply

How does the ERP determine GST tax period?
Are invoice date and supply date separately captured?
How are delayed invoices identified?
How are customer advances reconciled?
How are RCM liabilities identified from payment/book-entry data?
How is the 30-day RCM goods rule monitored?
How is the 60-day RCM services rule monitored?
How are foreign related-party services monitored?
How are continuous supplies tracked by milestone?
How are March unbilled services reviewed?
How are year-end provisions distinguished from actual taxable supplies?
How are rate-change transactions tested under Section 14?
How is the four-working-day payment proviso handled for rate changes?
How are interest/late-fee additions tracked?
How are GSTR-1 and GSTR-3B reconciled with time-of-supply workings?

14. 15 Common Mistakes

1. Using invoice date for every transaction RCM and rate-change rules differ.

2. Assuming payment date always controls Normal goods/services often use an earlier invoice trigger.

3. Ignoring statutory invoice period Delayed invoices can create earlier liability.

4. Treating accounting provision as GST liability Accounting and statutory triggers are different.

5. Ignoring customer advances Services require careful payment analysis.

6. Ignoring RCM Recipient-side timing can create liability.

7. Missing 30-day RCM goods test Creates delayed RCM compliance.

8. Missing 60-day RCM services test Common in imports.

9. Ignoring associated enterprises Special timing rule can apply.

10. Using old voucher rules Current Section 12 text records the 2025 omission.

11. Treating rate-change cases like normal invoices Section 14 has a separate matrix.

12. Using bank statement only The statutory payment definition can also refer to book entry.

13. Ignoring interest additions Specific time-of-supply rule applies.

14. Waiting for payment on government projects Payment delay does not automatically postpone GST.

15. No year-end time-of-supply review March services, advances and RCM can cross tax periods.

15. Time-of-Supply Decision Matrix

Question	What to check
Goods or services?	Start with Section 12 or Section 13.
Forward charge or RCM?	If RCM, use the special recipient-side timing rule.
Is invoice issued within prescribed time?	If not, Section 13 service timing can shift to another trigger.
Was payment received?	Check the statutory definition of payment date.
Is it a continuous supply?	Map contractual milestones and invoice/payment events.
Is there a rate change?	Stop and apply Section 14.
Is it foreign related-party service?	Check the special associated-enterprise provision.
Is it year-end provision?	Separate accounting accrual from GST statutory event.
What tax period?	Report GST in the period determined by time of supply.

16. Month-End & Year-End Time-of-Supply Checklist

InvoicesUnbilled servicesAdvancesRCMImportsMilestonesRate changesGSTR-1GSTR-3B

Control	Done?
All invoices issued within statutory time	☐
Customer advances reviewed	☐
Unbilled services reviewed	☐
RCM goods 30-day tracker checked	☐
RCM services 60-day tracker checked	☐
Foreign related-party services reviewed	☐
Continuous contracts/milestones reviewed	☐
Rate-change transactions tested	☐
Interest/late-fee additions reviewed	☐
GSTR-1 and GSTR-3B reconciled	☐

17. Frequently Asked Questions

What is time of supply?

It is the statutory point at which GST liability arises for the supply.

Does invoice date always determine GST?

No. Sections 12, 13 and 14 contain different timing rules, including payment, RCM, continuous supply and rate-change provisions.

Does payment always determine GST?

No. For ordinary forward-charge goods and services, invoice-related triggers can arise earlier.

Does a year-end provision create GST liability?

Not merely because an accounting provision was posted. The actual supply and applicable statutory time-of-supply trigger must be established.

What is the RCM time limit for goods?

Section 12(3) includes receipt of goods, payment and the date immediately following 30 days from the supplier's invoice/document, with the earliest applicable date controlling under the statutory rule.

What is the RCM time limit for services?

Section 13(3) generally uses payment or the date immediately following 60 days from the supplier's invoice/document, whichever is earlier, subject to its special provisions.

What happens when GST rate changes?

Section 14 overrides Sections 12 and 13 and applies a specific matrix based on supply, invoice and payment dates relative to the rate-change date.

How is payment date determined?

The statutory explanation generally uses the earlier of the date payment is entered in the supplier's books and the date it is credited to the bank account.

Are voucher time-of-supply rules unchanged?

No. The current Section 12 text records the omission of the earlier voucher-specific provision with effect from 1 October 2025. Businesses should use current law rather than older summaries.

Key Takeaway

The correct GST tax period should be determined through a structured process:

Identify supply → goods/services → forward charge/RCM → invoice timing → payment timing → special rule → rate-change test → time of supply → GST period → GSTR-1/GSTR-3B.

For construction, EPC, mining, government contracts and year-end closing, maintain a dedicated time-of-supply working for advances, RA bills, unbilled services, RCM and rate-change transactions.

GST Legal Reference Map

Section 12
Time of supply of goods.

Section 13
Time of supply of services.

Section 14
Change in rate of tax.

Section 31
Tax invoice timing.

Section 15
Value of taxable supply.

RCM 30/60-Day Rules
Sections 12(3) and 13(3).

Continuous Supply
Read Sections 12/13 with invoice provisions.

Rate Change Matrix
Section 14 before/after analysis.

2025 Voucher Change
Section 12(4) omitted effective 1 October 2025.