Skip to content

Trailer insurance and towing limits explained

If you’re planning on hitching a caravan, horse box or even a small box trailer to your car, here’s what you need to know about trailer insurance. And check out our comprehensive guide to towing limits and laws.

If you’re planning on hitching a caravan, horse box or even a small box trailer to your car, here’s what you need to know about trailer insurance. And check out our comprehensive guide to towing limits and laws.

Written by
Rory Reid
Car and technology expert
Last Updated
10 AUGUST 2023
7 min read
Share article

What is car trailer insurance?

Trailer insurance is standalone cover you can buy to protect the many types of trailers you can tow with your car, including:

  • Horse boxes and other animal trailers
  • Utility trailers
  • Trailer tents
  • Folding caravans
  • Boat trailers
  • Flatbed trailers
  • Garden trailers
  • Luggage trailers.

Your car insurance policy will typically only cover a towed trailer for third-party damage. This means if your trailer damages another vehicle or property, your insurance could cover the other person’s costs.

Car trailer insurance can pay for repairs to your trailer, or for a replacement, if it’s damaged while being towed, or stolen or damaged maliciously when parked. And depending on the policy, it could even cover what’s inside too.

Please note that you can’t compare trailer insurance with Compare the Market.

What does car trailer insurance cover?

Trailer insurance will typically cover your trailer for:

  • Accidental damage
  • Third-party damage
  • Fire damage
  • Theft.

Depending on the policy, trailer cover may also include:

  • The contents of your trailer
  • Towing in Europe
  • A replacement trailer to use if yours is out of action after an insured incident
  • The cost of transporting your trailer to and from repairs after an insured incident
  • Lending your trailer to family or friends.

Cover can vary depending on the provider, so check the policy carefully to see exactly what’s covered.

What is not covered by trailer insurance?

You typically won’t be covered by trailer insurance if:

  • You use your trailer for business or commercial use
  • You hire out your trailer for financial gain
  • The trailer is not roadworthy or safe
  • You break any towing laws.

As a condition of your trailer insurance, you may also need to comply with certain security measures, such as securing a wheel clamp to your trailer when it’s not in use.

Do I need specialist insurance to tow a caravan?

It’s not essential, but a specialist caravan insurance policy provides a higher level of cover than standard car insurance, which only covers third-party damage when you’re towing a caravan.

Specialist caravan insurance could cover your caravan when it’s parked and when it’s being towed. You could claim for damage to your caravan and you may even be able to cover the cost of a hire caravan or alternative accommodation if your caravan is damaged beyond repair.

A specialist policy might also offer cover if your caravan is stolen and your belongings inside are damaged or stolen.

See what else caravan insurance can cover.

How much can I tow?

You’re restricted by your car’s towing capacity. This is the maximum weight your vehicle can legally tow. You can find this:

  • In the owner’s manual
  • On your vehicle’s VIN plate. This is typically found inside the driver’s door or under the bonnet. The VIN plate should detail your car’s ‘gross train weight’.  This is the maximum combined weight of your car and trailer when fully laden and should not be exceeded. If the VIN plate doesn’t list a train weight, you shouldn’t be towing anything at all.

Although it’s not a legal requirement, many experts refer to the 85% rule when calculating how much weight it’s safe to tow. Under the 85% rule, the loaded weight of whatever you’re towing should be no heavier than 85% of your towing vehicle’s kerb weight.

The kerb weight is the weight of the vehicle without any passengers, luggage and so on. You should be able to find the kerb weight by looking in the owner’s manual or on your V5C registration certificate.

But how much you’re legally allowed to tow also depends on when your driving licence was issued.

What is MAM?

MAM, or maximum authorised mass, is the weight of a vehicle including the maximum load that it can safely carry – including passengers, fuel and load. It’s also known as the gross vehicle weight (GVW) or permissible maximum weight.

What is gross train weight?

This is the total weight of the vehicle that’s doing the towing, plus trailer plus load. It’s sometimes called gross combination weight (GCW).

Licence dates and towing restrictions

A standard category B licence allows you to drive a car and also gives you a towing allowance up to a certain weight.

However, the rules have become stricter over the years and the amount you’re allowed to tow depends on when you got your licence. So, you’ll need to know your driving licence category and when it was issued.

Licences issued before 1 January 1997

If your licence was issued before this date you can:

  • Drive a towing vehicle and trailer with a combined MAM of up to 8,250kg
  • Drive a minibus with a trailer over 750kg MAM.

Licences issued from 1 January 1997

If your licence was issued from this date you can:

  • Tow a trailer with a MAM of up to 3,500kg – as long as it’s no more than the unladen weight of the towing vehicle.

What size trailer can I tow?

To stay legal when driving on UK roads, your trailer must be no wider than 2.55m.

Towing vehicles with a gross vehicle weight of 3,500kg are also restricted in terms of the length of trailer they can tow. The trailer must be no longer than 7m, not including the A-frame.

How to weigh a trailer and caravan

You can find out how much your trailer or caravan weighs by taking it to a weighbridge. Weighbridges are designed to weigh all sorts of vehicles and you can find them up and down the country.

They used to be free, but it’s now quite common to pay a small fee. Find your nearest weighbridge at GOV.UK.

When using the weighbridge, weigh both the vehicle and the trailer or caravan:

  • Empty
  • Full
  • Together
  • Separately.

Make a note of each weight to ensure they meet the legal requirements. If you do go over the limit, you’ll need to unload some of the goods into another vehicle before driving away.

Penalties for driving an overweight vehicle and trailer

You can be given a fixed penalty fine if you drive an overweight vehicle. And you could be issued with a court summons if:

  • The offence is serious – for example the vehicle is overloaded by 30% or more
  • The excess weight and the way the load is carried has a significant effect on road safety –  for example, serious instability or loss of control.

Carrying excess weight could also invalidate your insurance.

What other towing rules should I be aware of?

  1. Number plate: the number plate on your trailer must be the same as the one on your towing car.
  2. Tow bars: the tow bar must be designed for your car and meet EU regulations
  3. Speed limits: the speed limits for cars towing caravans or trailers are: 
    – 30mph in a built-up area, unless otherwise stated. 
    – 50mph on a single carriageway 
    – 60mph on a dual carriageway or motorway.
  4. Motorway lanes: it’s illegal to tow a trailer or caravan in the outside lane of a three or four-lane motorway.
  5. Towing mirrors: if your caravan or trailer is wider than any part of your vehicle, you’re legally required to use towing mirrors. You can be fined up to £1,000 and get 3 penalty points for towing without proper towing mirrors.
  6. Trailer brakes: your trailer must have working brakes if it weighs over 750kg when loaded.
  7. Trailer lights: all lights should be working, including side lights, brake lights and indicator lights, as well as a pair of red reflectors on the back of the caravan or trailer. If your trailer is wider than 1.3m, you should also have a fog light. Trailers made since 1990 must have white reflectors at the front, unless they’re taller than 1.6m, in which case, you’ll need front lights.

Towing safety tips

Pulling a trailer, caravan or motorhome can take some getting used to, and reversing one is an art form. If you’ve never done it before, you might want to practice in a quiet field first.

Here are some top tips for safe towing:

  • Never overload your vehicle or trailer/caravan/motorhome.
  • Make sure loads are spread out safely and fastened down securely, and that nothing can fly out.
  • Make sure that all doors and catches are secured properly. Check any cables and make them secure.
  • Check your tyres and make sure they’re at the right pressure. If they’re underinflated, towing a caravan or motorhome can cause a tyre to blow out.
  • Hopefully this is obvious, but don’t tow a caravan or motorhome while people are inside it. Not only is this illegal, it’s also very dangerous.
  • Finally, take it easy. Your vehicle will handle very differently when towing a large trailer, caravan or motorhome, so make sure you stick to a safe speed, steer gently and check your blind spots often.

Read advice on towing safely from Mark Winn, Britain’s Chief Driving Examiner at the Driver and Vehicle Standards Agency (DVSA).

See the DVSA's recommended safety checks before you start towing with a car.

Frequently asked questions

When towing, what other insurance should I consider?

You may want to consider adding extra cover to your car insurance when towing a trailer or caravan. This could include:

  • Breakdown cover – breaking down when you’re on holiday, with half your belongings attached to the back of your car, isn’t fun.
  • European breakdown cover – for when your journey takes you abroad.
  • Courtesy car cover – to get you back on the road if your towing vehicle has to go into the garage for repairs.
  • Personal belongings cover – to cover whatever you’re carrying in your trailer or caravan against theft or damage.

Do I need to tell my insurance provider if I tow a caravan?

Yes, it’s a good idea to contact them to find out what cover you have for your car and caravan. If you don’t think the cover meets your needs, you may be able to add extras to your policy.

Alternatively, you may want to take out a specialist caravan policy.

Does home contents insurance cover a trailer?

Your trailer may be covered under your home contents policy while it’s stored in your garage or outbuilding.

If you have personal possessions cover, the contents of your trailer might be covered, but you’ll need to check your home contents policy to be sure. If you don’t have personal possessions cover as part of your contents insurance, you can usually pay to add it on.

Looking for a car insurance quote?

Compare car insurance quotes with us today and see if you could start saving.

Get a quote

Rory Reid - car and technology expert

Rory Reid is a car and technology expert. He serves as the main presenter on Auto Trader’s YouTube channel and was previously a host on BBC Top Gear and its sister show Extra Gear. He is also a presenter on Fifth Gear. Previously, he hosted Sky TV’s Gadget Geeks, CNET’s Car Tech channel, BBC Radio 5 Live’s Saturday Edition and on the YouTube channel Fast, Furious & Funny.

Learn more about Rory

Compare car insurance Get a quote