When you open a checking or savings account, you’ll be assigned an account number that identifies your individual account. Your account number is typically a string of 12 to 19 digits with the last four digits being your account type. These last four digits are known as your sub-account or identifier code and are unique to each bank, credit union, or other financial institution. Knowing your account number could come in handy in the event that you need to make changes to your debit card settings, transfer money between accounts or reset your online login username and password. With most banks and credit unions, the last four digits of an account are also part of an identification code called a RID—or Reply Identification digit—which helps the institution track statements and deposits more efficiently. In this blog post, we’ll explain what these numbers mean on your bank statement and how they can help you understand different types of accounts. Use the information below to locate your account number with the last 4 digits if it isn’t easy to find on your statement.