The NCT checklist is short if you split it in two: what the inspector tests, and what you can check yourself the evening before. Citizens Information puts the test at about 60 checks, done by computer and by hand, in 40 minutes to an hour. Most fails come from a handful of items you can see or fix cheaply.
What the NCT tests
The items and pass or fail standards are set out in the NCT Manual published by the Road Safety Authority, under EU Directive 2014/45. Citizens Information groups them like this:
- Brakes, including the hand brake.
- Exhaust emissions.
- Wheels and tyres.
- Lights, including headlamp aim.
- Steering and suspension.
- Chassis and underbody.
- Electrical systems, glass and mirrors.
- Transmission, interior and fuel system.
On top of that the inspector plugs a scanner into the OBD port. It reads the VIN, the odometer and any fault codes from the braking system (ABS and EBS) and, since May 2023, from the engine and emissions. For now those fault codes give an "advisory pass" if everything else passes, so the car does not come back for them alone. A lit eCall warning light is a fail. Towbars are tested too: the trailer socket output and wear on the ball.
The most common fail items
- Tyres. NCTS said in October 2025 that 182,160 cars (10.5%) failed on tyre condition over the previous 12 months, and 43,184 had tread below the legal 1.6mm. The RSA called tyres the leading cause of NCT failures.
- Headlamp aim. 140,602 cars (5.03%) failed on it in 2024, according to the NCTS FAQ.
- Suspension and steering, and brakes front, rear and hand brake. Citizens Information lists them with headlights as the points NCTS asks garages to look at in a pre-NCT service.
Pre-NCT checklist you can do at home
These come from the NCTS pre-NCT checklist, with the reasons NCTS gives for a fail. Ten minutes with a helper to watch the lights covers most of it.
- Tyres: tread at least 1.6mm, no cuts, bulges or damage, seated on the rim, valves sound. Pressures correct, since they also affect the brake and headlamp results.
- Wipers and washers: blades clear the screen properly, washer fluid topped up and aimed at the glass.
- Stop lamps: working, red, brighter than the tail lights, no water inside, lens intact.
- Indicators, side lamps and number plate lamps: working, right colour (amber, white, white), secure, no moisture.
- Headlamps: lens clean and dry inside, unit secure, bulb seated properly if you changed it, dipping correctly. NCTS recommends having the aim set before the test.
- Seat belts: not cut or frayed, and they lock and retract. All belts and clips visible, rear ones too.
- Horn: works and is securely mounted.
- Registration plates: both present, secure, legible and in the correct format.
Getting the car ready on the day
NCTS may refuse to test a car that is not prepared. Its own checklist asks for enough oil and water, an empty boot, clear seats, the glove box unlocked and empty for the OBD scan, hubcaps off where they hide the wheel nuts, a reasonably clean underbody and the engine at normal temperature. Bring your driving licence and the registration certificate. The full list, with why each item matters, is in our guide on what to bring to the NCT.
Once the car is ready, the next problem is usually the date. If the first slot on ncts.ie is weeks away, nctalerts.ie watches up to five centres and emails you within a minute when an earlier date appears. €9.99 for 7 days, and fewer than 3 alerts means an automatic refund.
Frequently asked
How many checks are in the NCT?
Citizens Information says about 60 different checks, done by computer and manually, taking 40 minutes to an hour.
What is the most common reason for failing the NCT?
Tyres. NCTS reported 10.5% of cars failing on tyre condition over the 12 months to October 2025. Headlamp aim is next in the NCTS figures, at 5.03% of tests in 2024.
Does an OBD fault code fail the NCT?
Not at the moment. NCTS records ABS, EBS and engine fault codes on the report as an advisory pass, provided everything else passes, and the car does not need to return for those items alone.
Is there an official NCT checklist?
Yes. NCTS publishes a pre-NCT checklist page listing the visual items and the reasons for failure, plus a printable preparation checklist. Both are linked below.
Are there new NCT test items in 2026?
We could not find an official NCTS or RSA notice of new test items in 2026. The last published additions were in May 2023 (OBD emissions codes, eCall, fuel consumption data). We will update this page if that changes.
Sources
Read on 24 September 2026. Fees, deadlines and phone numbers above come from these pages.