That's a good question.

I would be honest with the retailer and tell them what you want to do. They can then decide. Retailers all collect ID in different ways. So I cannot speak on behalf of all of them. Different Police Forces have different guidance and policies, so just ask.
They can always make a call and get advise - myself I cannot see any written answer to your question, so if you came into my shop I would just phone for advice. Nice and simple.

Hope that helps a small bit.

G

Thanks, I thought it would be a grey area,

It don’t matter where your from. As long as your over 18 with proof of ID. You can purchase a sub 12. Taking it to another country is down to the laws of the country you are going to.