Or another defense by law. In practice I find this not to happen all the time. For example I myself would be satisfied if the person was an established member of a forum such as this and could provide ID to verify he/she was over 18.
you just need to be over 18 and have a valid defense, most retailers only take ukara. GiantKiwi for second hand sales if the seller is happy then you can use any form of defense, i get the seller to ring up my local for confirmation as to who i am for my defense. Lord_mertile as long as no money/services or goods are exchanging between you and your mum she can buy it and then gift it to you.