Time of Supply under GST – Rules for Goods vs. Services

Introduction

The Time of Supply is one of the most important concepts under the Goods and Services Tax (GST) regime in India. It determines when the liability to pay GST arises on a transaction. Identifying the correct time of supply ensures timely payment of tax, accurate return filing, and compliance with the GST law.

The provisions relating to the time of supply differ for goods and services, and businesses must understand these differences to avoid interest, penalties, and disputes with the tax authorities.

This article explains the rules for determining the time of supply for goods and services under the Central Goods and Services Tax (CGST) Act, 2017, along with practical examples.

What is Time of Supply?

Time of Supply refers to the point in time when a supply of goods or services is deemed to have been made for GST purposes. It determines:

• The due date for payment of GST.
• The applicable GST rate (where rates change over time).
• The tax period in which the transaction must be reported in GST returns.

Why is Time of Supply Important?

Determining the correct time of supply helps businesses:

• Pay GST within the prescribed time.
• Avoid interest on delayed tax payment.
• Ensure correct reporting in GSTR-1 and GSTR-3B.
• Determine the applicable GST rate in case of rate changes.
• Maintain proper accounting and compliance.

Time of Supply for Goods

As per Section 12 of the CGST Act, 2017, the time of supply of goods is generally the earlier of:

1. Date of issue of the invoice by the supplier (or the last date on which the invoice is required to be issued), or
2. Date of receipt of payment.

Example 1

ABC Traders supplies goods on 10 July.

• Invoice issued: 10 July
• Payment received: 25 July

Time of Supply: 10 July

GST becomes payable in the tax period covering July.

Example 2

Invoice is issued on 20 August, but the customer pays an advance on 5 August.

• Advance received: 5 August
• Invoice issued: 20 August

Where GST is payable based on the applicable provisions, the earlier relevant event determines the time of supply.

Time of Supply for Services

As per Section 13 of the CGST Act, 2017, the time of supply of services depends on whether the invoice is issued within the prescribed time.

Case 1 – Invoice Issued Within the Prescribed Time

The time of supply is the earlier of:

• Date of issue of invoice, or
• Date of receipt of payment.

Example

Consultancy services completed on 5 September.

• Invoice issued: 15 September (within the prescribed period)
• Payment received: 30 September

Time of Supply: 15 September

Case 2 – Invoice Not Issued Within the Prescribed Time

If the invoice is not issued within the prescribed period, the time of supply is the earlier of:

• Date of provision of service, or
• Date of receipt of payment.

Comparison – Goods vs. Services

Particulars	Goods	Services
Governing Provision	Section 12	Section 13
Basic Rule	Earlier of invoice date (or last date it should have been issued) and payment	Earlier of invoice date (if issued within time) and payment
Delay in Invoice	Last permissible date for issuing invoice may become relevant	Date of provision of service may become relevant if invoice is delayed
Purpose	Determines GST liability	Determines GST liability

Time of Supply under Reverse Charge Mechanism (RCM)

For transactions covered under the Reverse Charge Mechanism, the rules differ.

Goods under RCM

The time of supply is generally the earliest of:

• Date of receipt of goods,
• Date of payment, or
• Thirty days from the date of issue of the supplier’s invoice.

If none of these can be determined, the date of entry in the recipient’s books of account may apply.

Services under RCM

The time of supply is generally the earliest of:

• Date of payment, or
• Sixty days from the date of issue of the supplier’s invoice.

If neither can be determined, the date of entry in the recipient’s books of account may apply.

Time of Supply in Case of Advance Payments

For services, receipt of advance may trigger the time of supply, subject to the applicable provisions.

For goods, businesses should follow the current GST provisions and notifications regarding the tax treatment of advances, as the law has evolved over time for different categories of supplies.

Change in GST Rate

When there is a change in the GST rate, determining the time of supply becomes particularly important because it decides whether the old rate or the new rate will apply.

The applicable rate depends on factors such as:

• Date of supply,
• Date of invoice, and
• Date of payment,

in accordance with the provisions relating to change in the rate of tax under the GST law.

Practical Examples

Example 1 – Sale of Goods

• Goods delivered: 12 June
• Invoice issued: 12 June
• Payment received: 28 June

Time of Supply: 12 June

Example 2 – Consultancy Services

• Service completed: 8 July
• Invoice issued: 15 July
• Payment received: 20 August

If the invoice is issued within the prescribed time, the time of supply is 15 July.

Example 3 – Reverse Charge Service

• Invoice date: 1 October
• Payment date: 20 October

The time of supply will be determined in accordance with the reverse charge provisions applicable to services.

Common Mistakes to Avoid

• Delaying the issuance of invoices.
• Reporting GST in the wrong tax period.
• Ignoring advance receipts where relevant.
• Applying incorrect GST rates after a rate revision.
• Incorrect determination of time of supply under reverse charge.
• Failure to reconcile invoices with books of accounts.

Best Practices

To ensure compliance:

• Issue tax invoices within the prescribed timelines.
• Record payments promptly.
• Reconcile books with GST returns regularly.
• Track advance receipts separately.
• Review GST implications before implementing rate changes.
• Maintain proper documentation supporting the date of supply, invoice, and payment.

Consequences of Incorrect Time of Supply

Incorrect determination of the time of supply may result in:

• Interest on delayed payment of GST.
• Notices from the GST Department.
• Penalties for non-compliance.
• Mismatch between books of accounts and GST returns.
• Cash flow issues due to incorrect tax reporting.

Conclusion

The concept of Time of Supply is fundamental to GST compliance because it determines the exact point at which GST becomes payable. While the general principle is based on the earlier of the invoice date and payment date, the detailed rules vary for goods, services, reverse charge transactions, and situations involving delayed invoicing or changes in GST rates.