CA Final · Indirect Tax Laws

Time of Supply for CA Final Indirect Tax Laws

Time of supply fixes the date on which GST becomes payable. For goods under forward charge, take the earlier of the invoice date (or last date to issue it) and the payment date. Under reverse charge, take the earliest of receipt, payment, or the day after 30 days from the supplier's invoice. Vouchers, interest and residual cases have their own rules.

What this chapter covers

Time of supply answers one question: on which date does the GST liability arise? That date decides the tax period in which you report the supply, the rate of tax that applies, and the point from which interest on late payment runs. The chapter gives a separate rule for each type of supply, so you must first identify the type and then apply its rule.

The chapter has four blocks. First, goods under forward charge, where the supplier pays tax. Second, goods under reverse charge, where the recipient pays tax. Third, the rules for vouchers, residual cases and interest, late fee or penalty charged for delayed payment. Fourth, special situations such as a change in the rate of tax, plus mixed practical problems.

This chapter sits between the levy and the invoicing provisions. It uses the invoice rules (when an invoice must be issued) and the reverse charge rules. Its output feeds value of supply, input tax credit and return filing. A wrong date here usually gives a wrong rate or a wrong tax period in the whole answer, which is why case-scenario questions on other chapters often test it indirectly.

Time of supply is rule-driven and short, so it is one of the easier chapters to score in. Questions are usually compact cases with several dates, and one correct reading of the rule gives you the full answer. The same skill also decides the tax period and rate in questions from other chapters, so a few days of careful practice pays off across the paper. In MCQs there is no negative marking, but a wrong date still costs you the mark. In written answers, stating the rule, applying it to the dates and giving the conclusion earns marks even if a later figure goes wrong.

Time of Supply: topics in the order to study them

1Time of Supply of Goods under Forward ChargeThis is the base rule (earlier of invoice date and payment date). Every other rule is a variation of it.
2Time of Supply of Goods under Reverse ChargeIt reuses the same idea but changes the trigger dates (receipt of goods, payment, 30 days from supplier's invoice), so study it right after forward charge to compare them.
3Time of Supply for Vouchers, Residual and Interest CasesThese are short, separate rules that apply when the main rules do not fit. They are easy to memorise once the two main rules are clear.
4Time of Supply Special Cases and Practical ProblemsRate-change situations and mixed problems need all earlier rules, so do them last to test your understanding.

How to prepare Time of Supply

Treat this chapter as a decision exercise. For each case, identify the type of supply, list the relevant dates, apply the rule and write the conclusion. Practice this routine until it is automatic.

Make a one-page comparison of forward charge and reverse charge for goods. Write the trigger dates side by side: invoice or last date to invoice and payment for forward charge; receipt of goods, payment and day after 30 days from the supplier's invoice for reverse charge.
Learn what counts as the date of payment. Forward charge uses the earlier of the date recorded in the books and the date the amount is credited to the bank account. Reverse charge uses the earlier of the date recorded in the books and the date it is debited in the bank account.
Practise with small timelines. Example: goods are received on 10 March, the supplier's invoice is dated 5 March, and payment is made on 20 April under reverse charge. The day after 30 days from the invoice is 5 April. The earliest of 10 March, 20 April and 5 April is 10 March, so that is the time of supply.
Practise the forward charge version. Example: the invoice is issued on 12 June and payment is received on 5 June. The earlier date is 5 June. Remember the optional treatment where excess payment up to ₹1,000 over the invoice value can be linked to the invoice date.
Learn the vouchers, residual and interest rules as three short sentences each. Voucher: date of issue if the supply is identifiable then, otherwise date of redemption. Interest, late fee or penalty for delayed payment: date the supplier receives it.
For rate-change cases, draw a timeline with the change date, then mark supply, invoice and payment on it. Apply the rule from your study material step by step. Do not guess from the dates alone.
Finish with mixed case scenarios under time pressure. Write each answer as rule, dates, conclusion, and check your reading of the dates before you check the arithmetic.

Common mistakes in Time of Supply

Using the supply or delivery date as the time of supply without checking invoice and payment dates.
Fix: List all dates in the case first, then apply the rule for that type of supply. Do not treat delivery as the answer by default.
Applying the forward charge rule to a reverse charge supply, or the reverse.
Fix: Read who pays the tax first. Write 'forward charge' or 'reverse charge' at the top of your working before picking dates.
Counting the 30-day limit wrongly under reverse charge for goods.
Fix: Add 30 days to the invoice date and then take the next day. Check this with a calendar example when you practise.
Taking the wrong date of payment, for example using only the cheque date.
Fix: State both dates and choose the earlier one, using the credit or debit wording that matches the charge type.
Forgetting the special rules for vouchers, interest and late fee, and using the general goods rule for them.
Fix: Keep them on a one-line card in your revision notes and solve at least one case for each.
Writing only a date with no rule or reasoning in descriptive answers.
Fix: Write provision, facts and conclusion. Even if your date is wrong, a correct rule statement can still earn part marks.

Last-day revision: Time of Supply

Time of supply decides the date GST liability arises, and so the tax period and the rate.
Goods, forward charge: earlier of invoice date (or last date to issue invoice) and date of receiving payment.
Date of payment (forward charge): earlier of the date entered in the books and the date credited to the bank.
Excess payment up to ₹1,000 over the invoice value: the supplier may choose the invoice date as time of supply for the excess.
Goods, reverse charge: earliest of receipt of goods, payment date, and the day immediately after 30 days from the supplier's invoice date.
Reverse charge: if none of these dates can be determined, use the date the recipient enters the supply in the books.
Voucher: date of issue if the supply is identifiable at that time; otherwise date of redemption.
Residual case: if a periodic return is required, the due date of the return; otherwise the date of payment of tax.
Interest, late fee or penalty for delayed payment of consideration: date the supplier receives it.
Rate change: mark supply, invoice and payment dates on a timeline against the change date, then apply the rule.
Always state the rule first, apply it to the dates, then conclude.
Check the type of supply before applying any rule. The wrong rule gives the wrong date.

Time of Supply practice questions

Time of Supply 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: frequently asked questions

What is the time of supply of goods under forward charge?

It is the earlier of two dates. One is the date of issue of the invoice, or the last date by which it should have been issued. The other is the date the supplier receives payment. Check the exact payment meaning in your study material.

How is time of supply decided under reverse charge for goods?

Take the earliest of the date of receipt of goods, the date of payment, and the day immediately after 30 days from the supplier's invoice date. If none of these can be found, use the date the recipient records the supply in the books.

Is Time of Supply an easy chapter in CA Final Indirect Tax?

It is rule-based and compact, so most students find it manageable. The risk lies in misreading dates and mixing up rules. Regular timeline practice usually fixes both.

How should I answer a time of supply question in the exam?

First name the type of supply and state the rule. Then apply it to the dates in the case and write the conclusion with the date and its effect, such as the rate or tax period. This provision-facts-conclusion format earns the most marks.