A nine-digit number identifying a specific bank or branch within the United States banking system. It routes domestic payments — such as ACH transfers and wire payments — to the correct institution.
Format: 9 digits, numeric only.
Example: 021000021 (JPMorgan Chase, New York).
ABA routing numbers are used exclusively inside the US banking system. For payments to or from Switzerland, the IBAN and BIC/SWIFT code play the equivalent routing role.
