I currently have a broadband internet account(installed yesterday), as a backup I have a dial up internet account, whilst testing the dial up account I noticed the telephone number being dialled was the correct number but was prefixed by 1470, is this something to do with my recently installed broadband ?(my original dial up account did not dial 1470).
I don't know about broadband but I have Virgin's 24seven service and the prefix 1470 has to be entered in the dialup if you have call waiting activated on the phone line or if you are ex-directory or if you have a 'number witheld' facility (i.e. the person you call cannot get your number by dialling 1471). There's some more details on Virgin's page at click here