Once you have signed up for online banking on the website for the bank at which you have an account, you can log into your account and transfer funds from your account to another at the same bank. If you want to transfer money between accounts at different banks, you'll need to perform an interbank transfer, which could take several business days. You'll need the bank name, routing number and account number for an interbank transfer. If you don't want to wait for the transfer, you can use your debit card at an ATM to take money from one account or use the cash-back feature when making a purchase. Once you take the cash from one account, you can either visit the other bank and deposit the funds or use the bank's ATM to make a cash deposit.