[JeffVW]

is it legal to put a untaxed uninsured car on a trailer and park the trailer on the
road?

[Beelzebub]

AFAIK you can't park a trailer on the road legally, no matter what it's carrying.

Very difficult to find relevant legislation but I imagine it's simply seen as an obstruction. FWIW this is what Lambeth Council say:

"Non-motorised vehicles/structures such as (but not limited to) caravans, trailers, horse boxes, and mobile catering units should not be stored/parked anywhere on the public highway (ie in bays, on yellow lines etc).
If a non-motorised vehicle/structure is stored/parked on the public highway it will be considered an obstruction and removed and may be disposed of."

[TC1474]

@JeffVW

Short answer is NO.

Any vehicle on a road (and being on a trailer is classed as being on a road) must be insured, taxed and have a current MOT.

The fact that the car's wheels are not in contact with the road surface has no relevance.

Additionally you may also be prosecuted for Obstruction

[Drivingforfun]

@TC1474

I thought no wheel contact does come into it? I often hear about how you can't tow an unroadworthy car if the wheels are touching the road, but you can transport it around on a trailer

I'm happy to be corrected

[TC1474]

Originally Posted by Drivingforfun

@TC1474

I thought no wheel contact does come into it? I often hear about how you can't tow an unroadworthy car if the wheels are touching the road, but you can transport it around on a trailer

I'm happy to be corrected

If it is parked up and not being transported then original statement stands.

You are right in that if being transported, fine, but it simply cannot be parked on the side of the road. There is a difference between parked and being transported.