Hi
I had to go through this issue of 'certification' of electronic copies of bills etc recently myself. I was fortunate in that our local public library has a JP come in about 3 times a week. What I did was to 'open' the document in front of them (ie login to my bank for example for online banking) and show then the 'original' on the screen. they then compared that with the printout i'd done earlier and they 'witnessed' that this was a 'true copy' of my bank statement from website
www.xxxbank ...... So you *might* want to lookup your local library and see if they offer a similar service (or your local citizens advice people)
HTH
Adrian