I'd imagine a mobile phone bill should be ok, as there should be a reference number on there which is used to basically confirm someone's identity. I'll double check when this group buy is full for ya, and I'll tell you all what you need to do when it's full.
As far as I'm aware I'll be sending off this list to the guy at Dubmeister, along with your email address's so he can confirm who's paying and check them off the list as you buy them from the site, resulting in a discounted rate, I think he said something about adding to the 'notes' section on the site who you are (GolfGTI.co.uk forum member) but as I said, I'll confirm this at the end

No problem with organizing this either, I was well chuffed with the plates, and only want the rest of fellow dubbers to enjoy them too, especially seeing as you'll get caught out sooner or later with German ones, or using your plain acrylic ones as standard lol!