Yes I could post to alt.uk.legal, but they might not know what a trailer is.

Really? Does the number plate have to be the same style as the one on the rear of a car?

Some years ago, when I could see, I saw a small trailer being towed with what looked like a hand painted number plate, but the tarp was held over the load by bungy chord one of which went over the so called number plate and under the bottom of the trailer wher it was secured. I'm sure it was safe, but Legal? I very much doubt it in today's world!

Brian

I'm sure a DIY numberplate (though not strictly legal) is viewed as being better than no numberplate or one that doesn't match the car. For a one-off towing (ie normally you use your own car but this time you are using a friend's car) are you really expected to take all your paperwork along to a place that makes up plates, and pay for a plate that you may only use once?

I had an interesting answer but the youtube account has been closed. It's a road train in India consisting of a tractor plus several 10s of ramshackle improvised trailers.

NT

If a tractor or other agricultural machine is towing a trailer the number plate on the trailer need not be the same number as the towing vehicle if (a) both number plates are registered to the same farm, and (b) the towing vehicle has two front number plates, one visible from each side.

Bill

Most european (as in not UK) countries have separate numbers for trailers, much more sensible in many ways. (I think)