How to check Cash App balance at ATM? I think I am the best person to answer this question because I have been using a Cash App for the last many years. And what I have liked the most is the fact that we can check the Cash App balance in multiple ways. The first simple method is simply just open the Cash App and see how much balance is left in your wallet. Another simple way is to check out the official website of the Cash App. If you have any doubts or find any discrepancy in your balance then consider dialling the Cash App customer service number.