A minor's bank account works in much the same way as an adult's account, except for the fact that the minor who owns the account usually can't make withdrawals: In states where minors can't open their own accounts, only the account custodian can make withdrawals. Typically, banks offer minor savings accounts rather than checking accounts, and you normally have to make in-person withdrawals at the bank rather than at an ATM. Under Federal Regulation D, you can make unlimited in-person withdrawals from savings accounts.
Locate the savings account withdrawal booklet for the minor's account. If you can't find the account booklet, you can find the account number listed on the most recent bank statement. If you can't find the account number, you must find out the minor's Social Security number: Bank employees can use that information to look up the account number.
Go to your local branch of the bank that holds the minor's account. Fill out the withdrawal slip and sign it. If you don't have withdrawal slips for the account, you can use a generic withdrawal slip, in which case you must also write the account number on the slip.
Give the withdrawal slip to a teller, along with a government-issued form of identification such as a passport or driver's license. Count the cash that the teller hands you and ask for a receipt with an account balance printed on it. Update the savings withdrawal register to record the amount of the withdrawal and the new account balance.