Tow a trailer with a car: safety checks
Checks you should carry out every time you tow a trailer, caravan or horsebox with a car, to make sure you're towing safely and legally.
The rules on what you can tow are different depending on when you passed your driving test.
Checks before you tow
Carry out the basic safety checks shown in this video to make sure that your vehicle and trailer are safe and legal.
You can be fined up to £2,500, be banned from driving, and get 3 penalty points for using a vehicle in a dangerous condition.
Tow ball and connections
- the trailer is correctly coupled to the towball or pin - follow the manufacturer’s advice
- the coupling height is correct
- the 7 or 13 core cable and plug isn’t damaged
Use a breakaway cable or secondary coupling. This engages the trailer’s brakes (if fitted) or stops the trailer if it becomes detached from the car.
- the cable isn’t worn or damaged
- there’s enough slack in the cable so that it doesn’t accidentally apply the brakes
- the cable won’t drag on the ground when you’re driving
Follow the manufacturer’s advice to make sure it’s connected correctly.
Wheels and tyres
Check that the tyres on both the car and trailer:
- don’t have any cuts or bulges
- are inflated to the manufacturer’s specification for the load being carried
Check that each tyre has a tread depth of at least 1.6mm:
- across the central three-quarters of the breadth of the tread
- around the entire circumference of the tyre
Check that the wheel nuts and bolts are tightened to the correct torque.
Check that mudguards are fitted to the trailer and they’re secure.
Lights and indicators
Check that there’s no damage to the lights, and that they’re all working correctly.
Load and weight limit
- the trailer isn’t overloaded
- the load is distributed evenly
- the load is secure
Find your car’s weight limit
The vehicle manufacturer’s plate gives information about weight limits for your car. Check the car’s handbook if a plate isn’t fitted.
|Weight 1||Maximum weight of the car on its own|
|Weight 2||Maximum weight of the car and trailer combined|
|Weight 3||Maximum weight for the front axle of the car|
|Weight 4||Maximum weight for the rear axle of the car|
The maximum weight includes passengers, other loads, and fuel.
Trailer with no braking system
The loaded trailer:
- must not weigh over 750kg
- should not weigh more than 50% of your car’s weight
Trailer with braking system
The car and loaded trailer must not weigh over the second weight shown on the car manufacturer’s plates.
The loaded trailer should not weigh more than 85% of your car’s weight.
When you’re driving
You must not drive faster than the speed limit for the type of road.
If the trailer starts to snake or swerve, ease off the accelerator and reduce your speed gently. It’s a sign that either:
- you’re going too fast
- the trailer is loaded incorrectly
Don’t brake harshly on a bend, as it makes the trailer unstable. Reduce your speed in plenty of time when approaching any hazard.
You must not drive in the right-hand lane of a motorway with 3 or more lanes.
The National Trailer and Towing Association guide to safe and legal towing gives detailed information about:
- attaching the trailer to the vehicle
- driving with a trailer
- maintaining a trailer
You can also order ‘Trailer towing guidance and the law’ from the Society of Motor Manufacturers and Traders (SMMT).
The Camping and Caravanning Club has a basic guide on how to tow a caravan.