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Vehicle type

Mobile Semi-trailer Roadworthy in Australia

Semi-trailers and B-doubles. COI required at periodic intervals depending on state, typically annual. Most semi-trailers need a Certificate of Inspection (COI) rather than a standard roadworthy. An HVRAS-qualified examiner is typically required to issue the certificate in QLD and NSW; equivalent rules apply in other states.

By state

NSWNew South WalesCalled: eSafety Check (Pink Slip)VICVictoriaCalled: Certificate of Roadworthiness (RWC)QLDQueenslandCalled: Safety Certificate (Roadworthy)WAWestern AustraliaCalled: WA Vehicle ExaminationSASouth AustraliaCalled: Vehicle InspectionTASTasmaniaCalled: Vehicle InspectionNTNorthern TerritoryCalled: Vehicle InspectionACTAustralian Capital TerritoryCalled: Inspection Report (Roadworthy)

Top metros for mobile semi-trailers

VIC

Reservoir

3073
VIC

Craigieburn

3064
VIC

Point Cook

3030
VIC

Berwick

3806
VIC

Melbourne

3000
NSW

Blacktown

2148
VIC

Pakenham

3810
NSW

Port Macquarie

2444
VIC

Werribee

3030
VIC

Glen Waverley

3150
NSW

Castle Hill

2154
NSW

Dubbo

2830

Before the inspector arrives

Tyres
Tread depth
Minimum legal tread is 1.5 mm across the central three-quarters of each tyre. Use a coin or tread gauge, if a 20-cent coin sits more than halfway in the groove, replace.
Pressure
Set to the placard pressure (usually inside the driver door jamb) when cold. Under-inflated tyres fail for sidewall flex and uneven wear; over-inflated fail for centre wear.
Sidewall condition
Check for bulges, cuts, cracks or exposed cords. Any sidewall damage is an automatic fail and a safety risk, replace before the inspection.
Lights
Headlights (low and high beam)
Both low and high beam must work on left and right. Aim should not be wildly off, a hazy, oxidised lens that cuts output also fails.
Tail lights
Both rear tail lights illuminate when the parking or headlights are on. Check for cracked lenses letting white light show rearward.
Brake lights
All three brake lights (left, right, high-mount) must light when the pedal is pressed. Get a helper to confirm, a dead bulb is the most common single fail.
Indicators
Front, side and rear indicators flash amber at the correct rate (60–120 per minute). Hazard switch must flash all four together.
Reverse lights
White reverse lights come on when reverse gear is selected with ignition on. Check both sides where fitted.
Number plate light
The white lamp over the rear plate must illuminate the entire plate at night. A blown bulb here trips a lot of inspections.
Brakes
Pedal feel
Pedal should be firm with no sponginess. It should not sink toward the floor when held under steady pressure with the engine running.
Parking brake
Hold the vehicle on a moderate slope. Lever or foot brake should engage within its rated travel and not release on its own.
Wipers and washers
Wiper blades
Blades clear the windscreen without streaking, juddering or smearing. Torn rubber is a common fail, blades are cheap to replace.
Washer jets
Both washer jets spray cleanly onto the windscreen. Empty bottle, blocked jet or split hose all fail.
Windscreen
Chips and cracks
No cracks longer than 30 mm or any damage in the driver wiper arc. Repair small chips with a windscreen kit before the inspection, replacements take days.
Suspension
Bounce test
Push down hard on each corner and release. The vehicle should rebound and settle within one or two oscillations. Excessive bounce indicates worn dampers.
Exhaust
Leaks and noise
No blowing sound from joints or holes, no excessive smoke, and noise level reasonable for the vehicle type. Black soot around joints is a leak indicator.
Seatbelts
All belts retract and lock
Every fitted belt must extend smoothly, retract under tension, and lock instantly when jerked. Frayed webbing or a sluggish retractor will fail.
Mirrors
Interior and both exterior
All three mirrors fitted, secure, and free of cracks. Power mirrors must adjust on both axes if originally fitted.
Horn
Horn operates
Horn sounds clearly from a single button press. A weak or intermittent horn fails.
Bodywork
Rust
Structural rust, sills, chassis rails, mounting points, suspension towers, is an automatic fail. Surface rust on panels is usually fine.
Sharp edges and panels
No torn metal, hanging trim or sharp protrusions that could injure pedestrians. Loose bumpers or dragging plastic must be secured.
Fluids
Engine oil
Check on level ground with a warm engine. Level between MIN and MAX, no milky contamination, no major leaks evident under the car.
Coolant
Coolant in the overflow bottle between MIN and MAX with the engine cold. No oily film and no obvious leaks at hoses or radiator.
Brake fluid
Reservoir between MIN and MAX. Fluid that is dark brown indicates age, flush before inspection if it is years old.
Number plates
Legible and securely fitted
Both plates fitted in the original mount points, all characters legible, no missing fasteners or cable-tied plates. A faded plate fails.

Semi-trailer inspection FAQs

Do all states accept a single semi-trailer certificate?
No, terminology and validity differ by state. Semi-trailers are inspected under the same federal vehicle standards, but the certificate is state-issued. Check your state guide for specifics.
Can a mobile inspector certify a semi-trailer?
Yes, but the inspector must be HVRAS-approved (in QLD/NSW) or hold the equivalent state authorisation to issue a COI for semi-trailers.
What is checked on a semi-trailer COI?
Brakes, steering, suspension, lights, tyres, body and chassis integrity. For heavy vehicles, additional structural and brake-test points apply.
How long does a semi-trailer inspection take?
Allow 60–120 minutes. Heavy and complex vehicles take longer than standard cars due to additional inspection points.