I have a contract to supply manpower to a factory for 12 months, whereby the recipient should make payment by the 15th of the succeeding month. When should I raise the invoice?

Given that the contract is for a period exceeding 3 months, to provide services on a continuous/ recurrent basis, the supply will be treated as a continuous supply of services. As the due date of payment is ascertainable from the contract, the invoice has to be raised on or before the due date of payment. (Section 31(5)(a) of the CGST Act).

(ICAI FAQ PUBLICATION 06-09-2017 -: Tax Invoice, Credit and Debit Notes : FAQ NO. 10)