I don't know about the U.K., but in the U.S., (may be some variations in state laws) minors cannot enter into a legal agreements - a parent or legally-appointed guardian must do so on their behalf.

(There's an exception for legally emancipated minors.)

So, technically, you have to enter into any agreements on behalf of your son.

Practically, I don't think there is generally any checking on this. Some registrars and hosts may ask about age, but I don't think it's commonly asked.

Generally, you have a credit card, (or perhaps PayPal account) you're good to go. Of course, a minor cannot have a credit card without a parent having signed for it. (Though I'm sure - given that they've been issued to cats, dogs, and goldfish, that more than a few slip through.)

An interesting side issue I've never really thought about - what, then, is the legal status of shrink-wrap licenses, EULAs, site terms and conditions, etc. with regard to minors?

Its over 30 years since my pre IT career required me to study contract law but IIRC as long as your son isn't entering into a credit agreement, and he has a suitable means of payment, then he can make a purchase. (Except for age restricted products of course).

I am not aware of any legal age restriction on domain ownership although your hosting service is perfectly entitled to make restrictions of its own.

has a suitable means of payment, then he can make a purchase

But this isn't a purchase.

It's a contractual agreement.

I would contact the hosting company or domain registrar and ask them if they allow minors to do contracts. If not, just be his legal guardian and do it for him.

Did a little research - apparently, in the U.S. contracts entered-into by a minor are voidable at the option of the minor, but become valid if the minor turns 18 without voiding the contract.

There are some exceptions - entertainment contracts, for example.

It is apparently NOT the case (as I had assumed) that such contracts are automatically void - but only if the minor decides at some point to void the contract.

The location of both hosting company and domain registrar will be significant. Use English suppliers and English law will apply.

thanks for your replies - my son purchased a few domains (co.uk & com) under his own name & i paid for them - there was no mention of age or minimum age submit on the application - i assume its ok?

i have another question in a new thread.