A BattleTag™ is a player-chosen nickname that identifies your Battle.net account in our games, websites, community forums, and more. Only one BattleTag can be associated with a Battle.net account.
BattleTags do not need to be unique. You can use any name you want, as long as it follows our Naming Policy. Each BattleTag is assigned a numeric ID to create a unique identifier (for example, FallenSlayer#3592).
To change your BattleTag, log in to your Battle.net Account Details and click Update in the BattleTag section.
Note: Each Battle.net account is allowed *one* free BattleTag change.