V50 2.0d ignition switch

Hi all, this is my first post on here, so please bear with me if the problem has been raised & answered numerous times. The ignition switch seems to have packed up on my v50. I went to turn key the other day - and nothing. Tried a few seconds later, then it started. After that, nothing at all. I understand this is a common problem. My question is that if I source a replacement from another vehicle, does it have to be a similar year to mine? Also, I take it a replacement has to come with its original key? Or, does my key have to be 'paired' to the replacement module?Thanks, Shaune