Was the expansion pass part of a physical deluxe or collectors edition (e.g. bundled card in the game case), or was it something separate purchased from a physical retailer? If you haven't already, try restoring licenses and see if anything is showing up under "ready to install": https://www.bungie.net/en/Help/Article/12181 Note that if you have multiple gamertag accounts, you need to be signed in as the one that used the code originally. Some of the retailer stuff will add credits to your gamertag account instead of directly purchasing the item. Then you would need to go through the xbox games store and purchase what you want.