Routing Number Validator
Validate US bank routing numbers (ABA/RTN) and check their authenticity.
What is a Routing Number?
A routing number, also known as an ABA (American Bankers Association) routing transit number (RTN), is a nine-digit code used to identify a financial institution in the United States for the purpose of transferring money.
Routing Number Structure
| Digits | Purpose |
|---|---|
| 1-2 | Federal Reserve routing symbol |
| 3-4 | ABA institution identifier |
| 5-8 | Specific institution code |
| 9 | Check digit (validation) |
Federal Reserve Districts
- 01 - Boston
- 02 - New York
- 03 - Philadelphia
- 04 - Cleveland
- 05 - Richmond
- 06 - Atlanta
- 07 - Chicago
- 08 - St. Louis
- 09 - Minneapolis
- 10 - Kansas City
- 11 - Dallas
- 12 - San Francisco
Checksum Algorithm
Routing numbers use a checksum formula for validation:
3(d1 + d4 + d7) + 7(d2 + d5 + d8) + (d3 + d6 + d9) mod 10 = 0
Where to Find Your Routing Number
- Bottom left of your personal checks
- Your bank's website or mobile app
- Bank statement
- By calling your bank
Quick Facts
- Always 9 digits
- Also called ABA or RTN
- Used for direct deposits
- Used for wire transfers
- Used for bill payments