Blizzard-supported guild banks were introduced with patch 2.3 to help reduce player-created guild banks, which were prone to Terms of Use violations due to account sharing.
Features[]
The guild vault seen by the guild leader
Access to the guild bank via a guild vault object next to the standard bankers in the game.
8 purchasable tabs which have 98 item slots each; bags are not required for the slots. The price for the first tab is 100, and increases for each successive tab, 250, 500, 1000, 2500, 5000, 10000, 20000, for a grand total of 39350.
Storage of money.
Players with the appropriate permissions can store items and money for use by the rest of the guild. The guild master can allocate different permissions to each tab as required.
Repair NPCs have a 'pay for repairs from guild funds' button based on guild permissions (up to withdraw limit).
Advanced permission system (defaults to controlled by guild leader) that can allow, disallow, and limit the interaction (deposit/withdraw items or money) per tab, per guild rank. Withdrawal limits can be set up.
Access logs in-game showing the 25 latest money- or item-related withdrawals/deposits per tab.
Web access and display via World of Warcraft Armory.[1] Requires login.[2]
, and increases for each successive tab, 250
4
[Guild Level 5]
[Stay Classy] 
Guild vault on the side of Darnassus bank.
Guild vault inside the bank of Exodar.
Guild vault inside the bank of Ironforge.
