The NCT is a check of basic requirements at the time the test is conducted. The NCT assesses components which are visible and accessible. It does not however replace your responsibility to ensure your vehicle is roadworthy at all times or the regular maintenance that a mechanic needs to carry out on your car. Vehicle defects found must be repaired and the vehicle must pass a re-test before the owner will be issued with an NCT Certificate.
In Ireland, National Car Testing or NCT applies to all cars over 4 years old and is a statutory requirement to pass every 2 years. Once a vehicle is more than 10 years old, the law dictates that each vehicle must pass the NCT test every year.