GST rates for maintenance services: reduced rates for housekeeping and aircraft/ship MRO, higher rate for general MRO. Heading 9987 assigns differential GST rates: housekeeping services supplied via an electronic commerce operator by unregistered suppliers qualify for a reduced rate provided no input tax credit on goods and services has been claimed. MRO services for aircraft (including engines and components) and for ships and vessels (including engines and parts) are placed in a reduced-rate category. Other maintenance, repair and installation services (except construction) not falling within the housekeeping or specified aircraft/ship MRO categories are subject to the higher general rate applicable to such services.