Is it a legal requirement now that if a car is taxed it has to be insured even if it is not being used on the road?

Selling my daughters car. Daughter is having wifes car and new one for my wife might arrive a couple of days before my daughters is sold.

yes unless the car is SORN.

Not worth sorn ing it for a couple of days, only a months tax left and was going to leave it on to make it easier for the buyer to drive away.

Dont think it's com in yet anyway
http://www.locostbuilders.co.uk/forum/51/viewthread.php?tid=151090

It is in force currently from what I read ("early 2011" but, from the Gov website:

What will happen if your vehicle doesn't have insurance

If a vehicle does not have insurance, the registered keeper of it could:

* receive a fixed penalty of £100
* have their vehicle wheel-clamped, impounded, or destroyed
* face a court prosecution, with a possible maximum penalty of £1000

An Insurance Advisory Letter (IAL) will be sent to inform the registered keeper of a vehicle that appears to have no insurance. It advises the keeper what actions to take to avoid receiving a Fixed Penalty Notice.

i.e., if you've forgotten you'll get a warning. Which is fair enough?

Warning shouldn't come for at least a few weeks, so I wouldn't worry about it, but be ready to insure/SORN it if you get a letter through the post.

All the communications have said that you WILL first receive a reminder/warning (however you want to see it) - you won't just get landed with a fine.

When you transfer the insurance, ask them to also continue covering the old car for a few days (until the end of the month)

Most insurers will do this for a reasonable fee....