@Albiscuit what is a defense. I'm I just being dumb or something?
Edit: I would be buying the gun online if that changes anything
Essentially to legally sell a RIF (Realistic Imitation Firearm = Painted black or whatever the real colour of the gun is) to someone, the shop owner needs to see a "defense" which is basically to prove you're buying the RIF for airsofting, or reenactment, or to use in the theatre etc.
Different hobbies will have different ways of proving this. In Airsoft, the predominant way of proving this is the "UKARA" scheme, which where you play 3 games over a certain period of time and get logged into the UKARA database. Shop owners can look you up to make sure that you're an Airsofter. You have to be over 18 to hold UKARA membership.
Unfortunately buying the gun online doesn't change this.
With this in mind, if one or both of your parents were to play at 3 airsoft games at your closest site, they would be able to register for UKARA and then buy the RIF you want.
If they don't, they'll need to buy an "IF" (imitation firearm) which is an airsoft gun with at least half of its body in a bright colour - Blue, Red, Green etc.
