Mobilisation advances under a works contract are treated as...

Mobilisation advances under a works contract are treated as consideration for supply, and works contracts are treated as services; accordingly the advance is a payment for the supply. Time of supply for such services follows the provisions applicable to services, permitting an invoice for an advance to be issued before provision of service. Absent issuance of an invoice within the prescribed period, the liability to pay GST arises on the date of receipt of the advance. If an invoice for the advance is issued within the period prescribed under the invoicing provision, tax liability is the earlier of invoice date or receipt date.