A Routing Transit Number (RTN) is an important way to identify a bank or other financial institution. It is a nine-digit number that is assigned to each financial institution in the United States by the American Bankers Association (ABA) in 1910. RTNs are used to send and receive payments, such as direct deposits and wire transfers, both domestically and internationally.

An RTN makes it much easier for payment processors to identify the financial institution that the payment is intended for. This helps to reduce processing errors because the payment will be sent to the correct place every time.

RTN's are unique in that they also help identify the country and region a particular bank or financial institution is operating in. This is because the first two to four digits of the number denote the Federal Reserve district or a state.

For international transfers, RTNs are sometimes in the form of an IBAN (International Bank Account Number) or a SWIFT (Society for Worldwide Interbank Financial Telecommunication) code. This is because RTNs are only used in the United States while an IBAN and SWIFT code are used globally.

In order to complete an online bank transfer or direct deposit, financial institutions will usually require the RTN of the recipient institution. In order to look up a bank’s RTN, consumers may search online or check their monthly statement.

Overall, RTNs are an incredibly important way to identify a bank or other financial institution in the United States. This helps to ensure payments are sent to the right place and reduces processing errors. Additionally, RTNs are used to identify a banks country and region of operation for international transactions.​