Not that I have a thing about British Gas all of a sudden, but I was just paying my gas and electric bills on house.co.uk, their cranky, temperamental, slow web site. It gave me the usual dropdowns for card start and expiry dates.
But both have ranges 1900 to 2999. See the screenshot!
Yes, of course you can also select a start date in the future and an expiry date in the past.
Avaragado's blog 
House
It sounds like they modelled the website after the TV series of the same name. Has that come out in the UK yet? Hugh Laurie is amazing in it.
Re: House
Yes, it’s on five (rebranded from Channel 5). Which explains why I’ve never watched it.
Re: House
I use them new fangled DVD thingies which don’t require any form of TV reception.