‘Continuous supply of services’ in terms of Section 2(33) of the CGST Act, 2017 means supply of services which is provided, or agreed to be provided, continuously or on recurrent basis, under a contract, for a period exceeding three months with periodic payment obligations and includes supply of such service as the Government may, subject to such conditions, as it may, by notification, specify.
In terms of provisions of Section 31(5) –
(a) Where the due date of payment is ascertainable from the contract, the invoice shall be issued on or before the due date of payment.
(b) Where the due date for payment is not ascertainable from the contract, the
invoice shall be issued before or at the time when the supplier of service receives the payment.
(c) Where the payment is linked to the completion of an event, the invoice shall be issued on or before the date of completion of that event.
The time of supply will be the date by which the invoice is actually issued or is required to be issued under the above provisions (a) and (c) or the date of receipt of payment (earlier of entry in books of account / credit in bank account), whichever is earliest.
(ICAI FAQ PUBLICATION 06-09-2017 : Time and Value of Supply -FAQ NO. 26)