Sidecar Law in the U.K.

This page attempts to answer questions regarding making your own sidecar and the legal responsibilities of the owner in the UK. This information was gathered first hand by talking to the Driver Vehicle and Licensing Agency (DVLA), the Vehicle and operator Service Agency (VOSA), the Department for Transport and my insurance company.

However this information is provided as a guide only. It is not a definitive reference for sidecar law and is just an understanding. It was written in 2015 and revised in 2023.
(Image from MCN)

Left or right sided chair?

All new sidecars must be mounted on the left of the motorcycle (as you sit on the bike) to be allowed to ride on U.K. roads. Visitors from abroad are exempt from this ruling, as are motorcycles which were U.K. registered before 1981. Specifically - machines registered in the U.K. before August 1981 can have the sidecar on either side.

The actual wording from UK C&U section 93 of the road vehicles regulations 1986 reads...

"No person shall use or permit to be used on a road any two-wheeled motor cycle registered on or after 1st August 1981 not being a motorcycle bought temporarily into Great Britain by a person resident abroad if there is a sidecar attached to the right (or off) side of the motor cycle."

Approval for homemade sidecars

For approval purposes there are two classes of sidecar builds.

Type 1 - A permanently attached sidecar welded to the bike frame to produce a single three wheeled vehicle.
With this type of build the bike frame might be modified and the sidecar would be fully integrated into the design.
This would be classed as a new vehicle and would need to be approved by VOSA which would test the new vehicle against the MSVA (Motorcycle Single Vehicle Approval) standards.
Once the bike has passed, it would be issued with a new 17 digit frame number, a registration plate starting with the letter Q and a new logbook.
Building a new vehicle like this would be similar to building a kit car and there are regulations for everything from the position of lights to the strength of welds.
It is worth noting that any lugs welded to the motorcycle frame or cuts made to it would deem it "radically altered" and, as such, would place it in this build category, even just for minor modifications of this type.
(image from bike EXIF)

Type2 - A bolt on sidecar.
Such a device, home made or purchased, is considered a motorcycle accessory and is therefore not subject to any approval. It is the equivalent of building a trailer and attaching it to your car. It is the responsibility of the owner to ensure that the sidecar is safely constructed, properly adjusted, matched to the bike and suitable for use on the road.
In the same way a trailer can be too big or badly matched to a towing car making it dangerous to drive; a sidecar can cause the same issues for the motorcycle. Additionally a sidecar affects motorcycle handling and riding style dramatically; it is therefore all the more important that it be constructed properly and with road safety in mind.

Once again, this category only applies to bolt on sidecars, strictly speaking if the motorcycle frame is modified in any way such as adding a lug to allow a sidecar to bolt on, then it should be checked by the MSVA process.

Insurance

You must inform your insurer of the sidecar fitment for your insurance to remain valid. The premium may change slightly but often it goes down rather than up. In my case my insurance already stated it was for "a motorcycle with or without sidecar" and so I just informed them that I was attaching a sidecar with no change to the policy.
As an aside; Taxation class remains the same for a motorcycle fitted with sidecar.

Rules and regulations

For all sidecars there are standards for lighting, tyre condition, wheel bearings and security to the bike; and so the bike and sidecar combination should be checked for road worthiness at the annual MOT test which all road vehicles have to have in the U.K.
Not all motorcycle testing stations can do combinations - you need to find one that can, for it to have the necessary checks.

Once the bike and sidecar have an MOT it is acceptable to remove the sidecar and ride the machine solo as the bike will have had all the necessary checks during the "combination" MOT. It is not acceptable to remove the sidecar for the purposes of the MOT and then re-attached it once the bike has passed. In any case, getting the sidecar checked is in the owner's interest for peace of mind and their own safety.

The UK MOT Manual lists the following items, additional to the standard motorcycle test, to be check on combinations.

Seat belts and helmets

Seat belt and helmets are optional for sidecar passengers, but the motorcycle rider and any pillion passenger must wear a helmet.
If seat belts are fitted they must be used and will be checked at the MOT test.

Lighting

The sidecar must be fitted with front and rear marker lights so the width of the vehicle is visible to other road users.
It should also have a brake light and reflector.
If the motorcycle has indicators then left hand set should be removed or blanked off and equivalent indicators added to the left hand side of the sidecar.

Specifications for obligatory sidecar lighting requirements are given in the table below. Correct at the time of writing (2015).
Fog lights, side reflectors and hazard lights are optional but there are specifications for these if they are fitted.