An ATM (also called Cash Machine in RCT2) is a stall guests use if they run low on funds. These are useful in pay-per-ride parks, as they allow guests to get more money to spend in your park, rather than leaving once they have spent the money they brought with them. If, however, these are not present, guests who have spent their money will see no point in staying in the park and will return home.

In parks with unlimited funds, cash machines are useless as guests do not use money (with the exception of the sandbox in RCT3).