Most bill counters are designed for U.S. currency. If you anticipate needing to count bills from other countries, you will need to do some research into what options exists for the currency of other countries.
You need to be aware that while some U.S. bill counters will count currency from other countries, the counterfeit measures may not work and that can cause a problem for your business.
Bill counters vary in terms of how quickly they count money. If you have a need to count a lot of money quickly, you will want to consider purchasing a bill counter with a large duty cycle and counting speed. You may possibly even need to consider purchasing more than one bill counter.
You may need your machine to do more than simply count the money. You may need your bill counter to also sort bills and create or add batches. There are electronic and digital models that will allow you to vary your options each time you use the machine.
If you have larger money handling needs, you need to look for a bill counter that can interface with other money handling machines for further processing.