Trial Key help

I have a trial key booklet which came with my CE of Nightfall, and one of them is for Factions or Prophecies(as you probably already know). I participated in that Factions beta ages ago and already own Prophecies. My question to you is, can I use the key on my account to play Factions for the trial period stated, or will it not work? Thanks in advance for any help.

Questions belong in the Q&A forum, and yes you can add it to your current account to try Factions.