Bind to Account (shown as Bind to Blizzard Account in-game, shorten as BoA or rarely BtA) is a form of item binding that was introduced in patch 3.0.2. Items that are BoA include heirlooms, Collector's Edition companions, rare archaeology artifacts, the 
[Baby Blizzard Bear], and the 
[Onyxian Whelpling]. Account Bound items can be mailed to any character that shares the same Battle.net account, regardless of faction or realm.
Patch changes[]
Patch 5.4.2 (2013-12-10): Players are now able to mail account-bound items to other characters that reside on a different realm on the same account. To send cross-realm mail: enter the character's name, followed by a hyphen "-", followed by the realm name. Note that cross-realm mail can only send account-bound items, not other items or gold. 
Patch 3.3.0 (2009-12-08): Bind-on-Account Items: Players can now mail Bind-on-Account items to characters on the same account and realm regardless of faction. Please note this only applies to Bind-on-Account items. Other items or gold cannot be sent via mail to characters on the same realm and account if they are from differing factions. - Patch 3.0.2 (2008-10-14): Added.
See also[]
- Heirloom
- Soulbound
- Bind on Pickup (BoP) or (rarely) Bind on Acquire (BoA)
- Bind on Equip (BoE)
- Bind on Use (BoU)