Advice?

public class App {

    public static void main(String[] args) {
        BankingSystem bankingSystem = new BankingSystem();
        bankingSystem.start();
    }
}


import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Random;
import java.util.Scanner;

public class BankingSystem {
    private final ArrayList<Customer> customers = new ArrayList<>();
    private final Scanner input = new Scanner(System.in);
    private final BigInteger randomID = new BigInteger(53, new Random());
    private final  Customer customer = new Customer();
    public void start() {

        Customer person = new Customer("Man",200);
        Customer tom = new Customer("Tom",500);
        addCustomer(person);
        addCustomer(tom);

        for (Customer s : customers) {
            System.out.println(s.getName() + " " + s.getBalance() + " " + s.getAccountID());
        }
        bankActions();
    }

    private void bankActions() {
        System.out.println("If you wish to deposit money press 1 \nIf you wish to withdraw money press 2\nTo exit press 3");
        int atm = input.nextInt();
        while (atm != 3) {
            if (atm == 1) {
                depositMoney(customer);
            } else if (atm == 2) {
                withdrawMoney(customer);
            }
            atm = input.nextInt();
        }
    }

    private void withdrawMoney(Customer customer) {
        System.out.println("How much do you want to withdraw?");
        int balance = input.nextInt();
        balance = balanceCondition(balance, customer.getBalance(), "You don't have enough money in the account.\nYour current balance is " + customer.getBalance());
        int withdraw = customer.getBalance() - balance;
        customer.setBalance(withdraw);
        System.out.println("Your current balance is $" + customer.getBalance());
    }

    private void addCustomer(Customer customer) {
        customer.setName(customer.getName());
        customer.setBalance(customer.getBalance());
        customer.setAccountID(randomID);
        customers.add(customer);
    }

    private void depositMoney(Customer customer) {
        System.out.println("How much do you want to add to your account?");
        int balance = input.nextInt();
        int BALANCE_LIMIT = 999999999;
        balance = balanceCondition(balance, BALANCE_LIMIT, "You can not add that much money at once. Add below $999999999");
        int addingToBalance = customer.getBalance() + balance;
        customer.setBalance(addingToBalance);
        System.out.println("Your current balance is $" + customer.getBalance());
    }

    private int balanceCondition(int balance, int i, String s) {
        while (balance > i) {
            System.out.println(s);
            balance = input.nextInt();
        }
        return balance;
    }
}

import java.math.BigInteger;

public class Customer {

    private String name;
    private int balance;
    private BigInteger accountID;

    public Customer(String name, int balance){
        this.name = name;
        this.balance = balance;
    }

    public Customer() {}

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getBalance() {
        return balance;
    }

    public void setBalance(int balance) {
        this.balance = balance;
    }

    public BigInteger getAccountID() {
        return accountID;
    }

    public void setAccountID(BigInteger accountID) {
        this.accountID = accountID;
    }
}