The Bank has two functions:
- Generates interest on the amount of money in the player's account, at the rate of 10% per interest period
- If "donated", it does not generate interest, but prevents a player from being responsible for paying property taxes.
Having multiple banks increases the amount of money generated for the player. However, the amount of interest earned does not increase on a linear basis, i.e., each Bank will not generate 10% interest on the player's money. Instead, the game acts to distribute the player's money evenly in each Bank, allowing a greater total rate of interest in the Banks, so there is an overall compound interest effect. As an example, if the player has a total cash balance of $1,000,000 and two Banks, $500,000 will be deposited in each Bank. The first Bank would generate 6% ($60,000) in interest, raising the total cash amount to $1,060,000. The second Bank would generate 6% interest ($63,600) on half that amount ($530,000) to raise the total amount in the player's account to $1,102,500. If the player has three Banks rather than two, each bank generates 4% interest on the player's money. Accordingly, while the difference between one Bank and two Banks is substantial in that two Banks will produce more than 20% more interest than one Bank on its own, the addition of a third Bank does not appreciably add to the interest generated and takes up funds that could otherwise be used for house construction.