The Bank's in Assassin's Creed Revelations will not automatically give you the money to spend. You will get a notification on your screen every 20 minutes advising you how much has been put in the bank's vault. To get access to this money you must travel to one of the Bank's on your map and choose the option to withdraw the money.
If you find the money is not accumulating as much as you thought, its possible the 20 minute timer has been intterupted. If any of the below occur during this time the timer will reset:
- Linear Game Sequences e.g. campaign missions.
- The Cappadocia section of the game.
- Den Defence.
- Altair's missions.
- Any mission is aborted.
Once any of the above take place in the game, the timer will reset and the full 20 minutes will need to pass again before a deposit is made.