text: I'm not exactly sure what you're meaning, but here's two answers.\n\nWith all banks giving credit to YOU, that depends on your FICO score.  Your FICO score determines how reliable you are as a lender. Most banks follow the same rates, depending on your FICO score, and all of them charge you similar amounts. \nWith banks loaning to each other, this is called a federal funds rate.  Banks actually prefer this over the Federal Discount Rate, which is when the Fed loans money to banks.\nThe Fed requires that banks keep a certain amount of money at all times.  This is called a Reserve Requirement.  This is checked periodically and is usually a percentage of total checking deposits.  To make this requirement, banks will loan to each other, thus satisfying the Fed and each bank.