In the same way that every financial account is assigned a unique account number, every financial institution is assigned a unique routing number. To protect account numbers from fraud, financial institutions may also use multi-factor identification, two-step verification, and other security measures.Įvery financial transaction involves at least two account numbers: one that indicates where the money is coming from, and one that indicates where it is going. Most bank account numbers have between 8 and 12 digits, though they can range from 5 to 17. In the United States, each bank assigns account numbers using its own methodology, kept private for security reasons. Since then, account- and routing numbers have helped to securely identify account holders and financial institutions, respectively. Financial account numbers as we know them today are thought to have originated when computers began to be used for banking in the late 1960s.
Examples of account numbers include routing numbers and credit card numbers.īank accounts have existed since ancient Mesopotamia, but the account number is a more recent invention. Almost all financial transactions make use of account numbers. An account number is a unique string of numbers, letters, and other characters that identify a specific financial account.