Roadworthy certification is required when: there is a change of ownership of a vehicle, the motor vehicle is reconstructed or altered, the motor vehicle or trailer was built up from parts and needs to be registered or when a motor vehicle has been issued with a notice to discontinue operation (Section 44) by a traffic officer and is subject to a full roadworthy test.
In the case of minibuses and heavy load vehicles such as trucks and trailers (GVM exceeding 3500 kilograms), an inspection needs to be done on a yearly basis in order to receive a roadworthy certificate (COF) whereas buses require this every 6 months.