When you do this, make sure you use the same account email you use for Origin so everything is added to the same account.
You still need to visit to buy and download Worlds or to redeem any bonus codes you have.You don’t need to follow the steps below if you bought The Sims 3, your expansion(s), or your stuff pack(s) through Origin – anything you buy on Origin is automatically added to your account.Find out how to redeem your game code, download and install The Sims 3, its expansions, stuff packs and worlds.
