Does your state have any regulations that address retention? requirements. Our state (NY) has an ATM Safety Law that states how long a tape must be retained, as well as how long it can stay in the machine, how many times it can be used, etc. Also has stringent ATM lighting standards. Check to see if your state has anything? A good rule of thumb is 3 months, as it may take a customer that long to figure out that there is a problem on their account.