Bank

A bank is a building with several teller NPCs that allow a character to access a private storage area that is accessible from any bank branch. Branches appear in major cities and some towns, and allow a character to store items not currently in use.

All of the banks share the same vault; the neutral banks are equivalent to the faction banks. If you place items in one bank, you will be able to access them in another. (Canonically, this is accomplished through the use of Automated Teleportation Modules; ATM's for short.) However, players are not able to use the banks of opposing factions, because they cannot talk to the tellers.

Bank space
Initially a character's bank account (vault storage space) contains 28 item storage slots at no cost. An additional seven bag slots for more space are purchasable. These provide no additional item storage slots, but allow placement of a bag that has item storage capacity. The bags can be changed out and it is common practice to progressively place larger bags. The cost of the bag slots increases with each extra slot purchased starting at, (then increasing to , , , , , , for a total of for all slots (not including the bags that go into them).

Unlike a real bank, you cannot store currency within the bank, only items.

Bank alts
A bank alt (or bank mule) is a character that is usually level 1 and sits in a trade city near the bank and the Auction House. This character's primary use is for:
 * 1) Extra bank space
 * 2) Auctioning items
 * 3) Managing numerous amounts of resources

Where can I find bank branches?
All of the Alliance and Horde capital cities have bank branches:

Horde bank branches

 * Thunder Bluff
 * Orgrimmar
 * The Undercity
 * Silvermoon City

Alliance bank branches

 * Ironforge
 * Darnassus
 * Stormwind
 * The Exodar

Neutral bank branches
Some neutral cities and towns have them as well:
 * Ratchet
 * Gadgetzan
 * Booty Bay
 * Everlook
 * Area 52
 * Shattrath City (Aldor/Scryer)
 * Dalaran (northern/southern and sewer)

Portable banks
Portable banks can be carried with players as items or abilities, giving access to the bank anywhere in the game. They reduce a player's need to travel to a bank, but, due to their long cooldowns (often an hour or more), they do not completely remove it.

Known portable banks:
 * Jeeves ( bank only accessible by engineers )
 * Argent Squire ( when upgraded with an Argent Pony Bridle )
 * Argent Gruntling ( when upgraded with an Argent Pony Bridle )
 * Pack Hobgoblin ( goblin racial ability )
 * Mobile Banking ( will access your guild bank )

Other uses of the term bank

 * Guild bank
 * Bank character