An annual test originally ordered by the Ministry of Transport (now Department of Transport, Local Government, and the Regions) to be carried out on all motor vehicles over a certain age to ensure that they comply with certain legal requirements relating to vehicle maintenance. The test covers brakes, steering, lights and indicators, windscreen wipers and washers, the exhaust system, horn, tyres (and to some extent, the wheels), bodywork and suspension (insofar as they affect the brakes and steering), and seat belts. It is an offence to put on the road a motor vehicle that has been registered for over three years (five years in Northern Ireland) without a valid test certificate. A certificate is issued for 12 months and must be renewed annually; a vehicle that is subject to a test cannot be licensed without a test certificate (see road tax). It is not an endorsable offence not to have an MOT certificate, but this may invalidate the motorist's insurance and result in a charge of driving without insurance. An MOT certificate does not indicate that the vehicle is roadworthy in all respects and is not a defence to charges brought under the vehicle construction and maintenance regulations.