If you own a base game of any kind (Normal, Tamriel Unlimited, Gold) then you can't add other base game codes to update the account, only create new accounts with them.
I believe the only code which works as an upgrade is the Morrowind one (just adds Morrowind).
@Turelus - EU PC Megaserver "Don't count on others for help. In the end each of us is in this alone. The survivors are those who know how to look out for themselves."
imperial edition IS tamriel unlimited with imperial race unlocked. you have a better edition of the game already. if you are talking about 15 days of subscription - that's a separate code. tamriel unlimited doesn't come with any dlc's btw. its just base game's new name since ESO was changed to one tamriel build (where you can play anywhere with anyone at any level, instead of having veteran zones for other alliances and level based zones for your alliance)
dirty worthless casual.
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