We explain the key registration steps, inspections and road rules so you can tow safely and meet state expectations right now. This guide gives clear, practical information on towing setup, checks and obligations for owners in South Australia.
We build and service custom trailers in Adelaide and see common faults every week. Working lights, sound brakes and correct wiring keep you moving and reduce downtime.
Licence and weight matters matter: a Class C covers vehicles to 4.5 t GVM; bigger loads usually need an LR licence. Follow your vehicle maker’s towing speed guidance and use towing mirrors if your view is blocked.
Practical checks are simple: use the correct safety chains and load heavy items low and near the axle. Check the compliance plate or VIN for ATM, tyre sizes and pressures before you hook up.
Want help with inspection, repairs or a quote? Call us on 0447 100 145 and we’ll sort your trailer for long life and safer towing.
Key takeaways
- Confirm your licence class and weight ratings before towing.
- Ensure lights, brakes, chains and wiring are roadworthy.
- Follow manufacturer speed guidance and rest every 2 hours on long trips.
- Keep heavy loads low and close to the axle for stability.
- Check the compliance plate/VIN for ATM and tyre details.
- Use towing mirrors and flag rear overhangs over 1.2 m.
- Contact Smooth Moves Trailers in Adelaide on 0447 100 145 for service or advice.
Why SA trailer compliance matters for your work, your gear and everyone on the road
A compliant setup reduces sway, lowers wear and keeps insurance valid, so jobs finish on time and on budget.
We build and repair using good materials and solid fabrication so your trailer tracks straight and the brakes bite cleanly.
Regular safety checks are simple and effective: lights, brakes, tyres, bearings, chains and couplings. Do these before each trip.
- Correct weight distribution protects brakes, tyres and bearings on both tow vehicle and trailer.
- Rated chains and D shackles keep equipment attached if a hitch fails.
- Good wiring and earths ensure drivers behind you see your signals.
- Mirror extensions help when you can’t see past a caravan or float.
Keep the rules in mind: width is limited to 2.5 m, total length to 19 m, and flags are required for rear overhang past 1.2 m. Follow these standards so trips stay safe across the state.
Simple pre-trip tips: check tyre pressures, test lights, feel hubs for heat and keep loads low and near the axle. Take a 20-minute break every two hours on long drives.
Book a safety check with us on 0447 100 145 and we’ll inspect registration, fitment and stopping systems so you can tow with confidence.
Trailer legal requirements South Australia: what you must have before you tow
Knowing what must appear on the compliance plate and VIN is the fastest way to pass pre-registration inspections. The plate and VIN list manufacturer, model, date, ATM, rim and tyre sizes, tyre pressures, axle load and tare/GTM.
Registration, exemptions and identity
New units with Vehicle Type Approval often skip identity inspections since 2018, but homemade or used trailers without proof need a VIN from Service SA and an identity check.
Registration requires proof of identity and an accurate compliance plate; without these you cannot use the trailer on the road.
Inspections and roadworthiness
ADR standards cover brakes, lights and tyres. We test wiring looms, earths and lamp operation so your unit meets the rules first time.
Mass, chains and dimensions
ATM and GTM must match the plate and your tow vehicle rating; check gvm limits and towbar figures against the manufacturer data. Chains and D shackles must be load-rated: one for under 2.5 t, two for 2.5–3.5 t.
- Max width 2.5 m; side protrusion max 15 cm.
- Combined length max 19 m; rear overhang >1.2 m needs a bright flag.
We supply compliance documentation for our builds and fix faults on used units so you pass first time. Call us on 0447 100 145 for a pre-rego inspection.
How to register a trailer in SA today
Before you visit Service SA, gather the compliance details and documents that speed up registration.
Get your VIN and compliance details
Start with the VIN. If your unit lacks one, Service SA can issue it and we can fit a plate that lists manufacturer, model, date, ATM, VIN, rim and tyre sizes, tyre pressures, axle load and tare/GTM.
Documents and fees to bring
Bring proof of purchase, a completed application for registration and third‑party insurance. Expect fees based on trailer class; we can advise what to budget so you aren’t surprised at the counter.
Do you need an inspection?
New builds with Vehicle Type Approval usually skip identity checks. Used or homemade units often need a VIN and an inspection. Book a pre‑rego check with us to sort lights, brakes, bearings and wiring before you queue.
Step‑by‑step at Service SA
- Present ID, proof of purchase and completed forms.
- Confirm VIN and plate details match your build.
- Pay applicable fees and collect your number plate.
We make registration simple: we fit correct plates, supply clear documents and prepare used units so you pass first time. Call us on 0447 100 145 to book a pre‑rego service or request a quote.
Road rules, towing limits and safe loading for South Australian roads
Towing safely starts with matching your vehicle ratings and load to road limits and good driving habits. We cover licence classes, speed guidance and practical checks so you can plan trips with confidence.
Licence classes and vehicle ratings
Class C covers most cars and utes up to 4.5 t GVM. If your tow setup or combination exceeds that, an LR licence is needed.
Match ATM to your towbar and vehicle rating so you do not overload brakes, tyres or drivetrains.
Towing speed guidance and interstate differences
Follow manufacturer speed guidance for your setup and keep speeds conservative. Different states set different maximums, so check limits before you cross borders.
Use slow‑vehicle lanes when safe and allow extra stopping distance when towing heavy loads.
Mirrors, visibility and managing sway
Fit extension mirrors with a caravan or a float so you can see lane markings and following traffic.
If a heavy vehicle passes and your unit sways, keep a steady wheel, reduce speed gently and give it space until the effect stops.
Loading right and axle position
Balance weight low and close to the axle. Aim for a steady tow‑ball load and secure gear with rated tie‑down points to prevent movement under braking.
Pre‑trip checks
- Test lights, wiring and earths so signals work reliably.
- Check tyre pressures and hub temperatures.
- Inspect coupling latch, safety chains, D‑shackles and any breakaway system.
Want us to check bearings, brakes and wiring? Book a safety service on 0447 100 145 and we’ll prepare your unit for safe towing on SA roads and interstate trips.
Keep it roadworthy: servicing, inspections and when to see us
Keep your unit roadworthy with scheduled servicing and simple checks so faults don’t ruin a job. Routine attention stops wear turning into failure and keeps your equipment safe on the road.
Real jobs we see in Adelaide
- Brakes: glazed shoes, seized adjusters and hot hubs — we skim drums, fit new shoes and set clearances so braking returns to spec.
- Tyres: cracked or flat‑spotted rubber — we match tyre load and pressure to the item weight and recommended speeds to cut heat and blowout risk.
- Electricals: bad earths cause intermittent lights — we rerun earths, solder and heat‑shrink joins, then seal looms so indicators work every trip.
- Axles & suspension: bent axles or sagging springs wear tyres — we replace axles, shackles and bushes, then align so the unit tracks straight.
Good materials and fabrication that last
We use quality steel, rated chains and D‑shackles, sealed looms and proper couplings. Strong welds and plated repairs handle site conditions and reduce repeat visits.
Why each fix matters: reliable brakes, correct tyre matching and solid axles protect vehicle drivetrains, retain insurance cover and help pass inspections with fewer fees.
- We service hubs, springs, bearings, wheels and lights to meet standards.
- Torque wheel nuts, recheck after 50 km and carry a compatible jack and wheel brace.
- Regular servicing keeps registration simple and reduces surprise fees from failed checks.
Book a safety check in our Adelaide place today. Call 0447 100 145 to arrange servicing or request a quote.
Conclusion
A practical final checklist keeps registration and towing simple.
Check the compliance plate and VIN, confirm registration paperwork and match ATM or gvm to your tow vehicle. Follow manufacturer speed guidance and fit mirror extensions if visibility is limited.
Keep safety first: working lights, sound brakes, rated chains and secure loads protect the owner and other road users. Remember SA limits — 2.5 m width and 19 m overall — and flag any rear overhang past 1.2 m.
We inspect, fix and document so your unit meets compliance and passes inspections with fewer fees. For builds, servicing or quick advice, call Smooth Moves Trailers on 0447 100 145 to book a service or request a quote.
FAQ
What registrations and identity plates are required before we tow?
You must register any trailer that meets state thresholds. Registration involves a unique plate and a VIN or compliance plate for manufactured units. Homemade floats may need an identification plate issued through Service SA after inspection. We recommend carrying proof of purchase and any compliance paperwork when you visit a Service SA centre.
When is an inspection necessary to prove roadworthiness?
An inspection is usually required for homemade or modified trailers, and for some used imports. New manufactured units with a valid compliance plate can bypass initial checks, but any trailer with suspected faults—brakes, lights or structure—should be inspected. Service SA or an approved workshop will check ADR compliance, wiring, brakes and tyre condition.
How do we determine acceptable mass and axle ratings for our tow vehicle and load?
Check the manufacturer plate on both the tow vehicle and the trailer for ATM, GTM and GVM figures. These numbers tell you maximum allowable loaded mass and axle loads. Never exceed the vehicle’s towbar rating or the trailer’s ATM. Overloading leads to unsafe handling and legal penalties.
What braking systems do we need depending on trailer weight?
Braking requirements change with mass. Light trailers under the threshold may rely on the tow vehicle’s brakes, while heavier trailers need overrun or electric brakes and a breakaway system. Safety chains or D shackles are mandatory as a backup when the coupling fails.
Are there rules for width, length and overhang for loads in SA?
Yes. Standard width limits apply, and any load that overhangs must be flagged or lit according to daytime and night rules. There are specific maximums for length and permitted overhang; check with Department for Infrastructure and Transport or Service SA for current dimension limits and escort requirements for wide loads.
What documents and fees do we need to register at Service SA?
Bring proof of identity, proof of ownership (receipt or transfer), any compliance plate or VIN documentation, and current insurance if required. Fees include registration, transfer and inspection charges where applicable. Service SA lists current fees online and at their counters.
How do we get a VIN or compliance plate for a homemade trailer?
Register the trailer as a constructed vehicle by booking an inspection with Service SA or an authorised inspection station. An inspector will verify build quality, axle and braking systems, and may issue a VIN or approval plate once standards are met.
What licence class do we need to tow different trailer masses?
A standard Class C licence covers most light towing. For heavier combinations you may need a higher class such as Light Rigid (LR) or other endorsements. Check your licence conditions and the tow vehicle’s permitted combination mass to ensure compliance.
Are there speed limits or interstate differences we should consider?
Speed limits can vary between jurisdictions and depend on trailer mass and vehicle class. When crossing state borders, confirm local speed rules and towing laws. We advise reducing speed when towing heavy loads and adjusting for wind and road conditions.
What pre-trip checks should we perform before every journey?
Check lights, indicators, and wiring; inspect tyres for correct pressure and damage; confirm couplings, safety chains and D shackles are secure; test brakes and breakaway systems; and ensure the load is tied down with correct anchor points and balanced over the axle.
How should we load to maintain stability and avoid sway?
Place about 60% of the load forward of the trailer axle(s) to maintain correct nose weight. Keep heavy items low and centred, secure everything with rated tie-downs, and avoid loose items that can shift. If sway occurs, gently slow down and avoid abrupt steering inputs.
When should we service or replace parts to keep the unit roadworthy?
Service brakes, wheel bearings and suspension at regular intervals or if you notice noise, vibration or reduced braking. Replace cracked tyres, damaged wiring looms, corroded welds and worn couplings promptly. Regular checks prevent roadside failures and keep compliance intact.
What common faults do we see in Adelaide workshops?
We regularly find glazed or seized brakes, cracked or bald tyres, poor earths causing intermittent lights, and weakened welds around suspension mounts. Addressing these issues early avoids fines and increases safety for everyone on the road.
Do we need insurance for our trailer?
While compulsory third-party insurance applies to motor vehicles, trailers may not always require separate cover. However, we strongly recommend comprehensive or contents cover for valuable loads, and liability cover if you tow commercially or rent out equipment.