Routing Number Validator
Type a 9-digit US bank routing number (ABA routing transit number) to check its format and checksum instantly. The tool shows which Federal Reserve district the prefix belongs to, the corrected check digit if there is a typo, and the full calculation. Bulk mode checks whole lists and exports CSV.
Last updated:
Spaces and dashes are ignored. The routing number is the 9-digit number at the bottom left of a US check.
| # | Input | Result | Type | Fed district | Note |
|---|
Checks the format and checksum only, in your browser. A valid checksum does not prove that a bank or account exists; confirm payment details with the bank.
How to use the Routing Number Validator
- Type or paste the routing number; the result updates as you type.
- Read the verdict: valid or invalid, with the reason when it fails.
- Check the details: prefix type, Federal Reserve district and the digit breakdown.
- Look at the step-by-step checksum to see exactly why the number passes or fails.
- For many numbers, open Bulk check, paste one per line and download the CSV.
Anatomy of an ABA routing number
The American Bankers Association introduced routing transit numbers in 1910 so that checks could be sorted and sent to the right bank. Every routing number has nine digits in the pattern XXXX YYYY C:
| Digits | Name | Meaning |
|---|---|---|
| 1–2 | Prefix | Federal Reserve district (01–12) and institution type (see below) |
| 3–4 | Fed office code | Together with the prefix forms the Federal Reserve routing symbol; it identifies the Federal Reserve office/check-processing center the number was originally assigned to |
| 5–8 | ABA institution identifier | Identifies the bank, credit union or thrift within that Fed area |
| 9 | Check digit | Calculated from the first eight digits so the 3-7-1 weighted sum is a multiple of 10 |
Routing number prefixes and Federal Reserve districts
| District | Letter | Federal Reserve Bank | Bank prefix | Thrift prefix | Electronic prefix |
|---|---|---|---|---|---|
| 1 | A | Boston | 01 | 21 | 61 |
| 2 | B | New York | 02 | 22 | 62 |
| 3 | C | Philadelphia | 03 | 23 | 63 |
| 4 | D | Cleveland | 04 | 24 | 64 |
| 5 | E | Richmond | 05 | 25 | 65 |
| 6 | F | Atlanta | 06 | 26 | 66 |
| 7 | G | Chicago | 07 | 27 | 67 |
| 8 | H | St. Louis | 08 | 28 | 68 |
| 9 | I | Minneapolis | 09 | 29 | 69 |
| 10 | J | Kansas City | 10 | 30 | 70 |
| 11 | K | Dallas | 11 | 31 | 71 |
| 12 | L | San Francisco | 12 | 32 | 72 |
Prefix 00 is used by the US Government and 80 by traveler's checks. Banks that merge or move often keep their original routing number, so the district shows where the number was first issued, not necessarily where the bank is today.
Worked example and validation tips
Take 021001208: 3×(0+0+2) + 7×(2+0+0) + 1×(1+1+8) = 6 + 14 + 10 = 30. Thirty is a multiple of 10, so the checksum passes. Change any single digit and the total stops being a multiple of 10.
- Validate on input, not just on submit. In payment forms, check length, digits only, prefix range and checksum before the user continues.
- Store routing numbers as text. Many start with 0, and saving them as integers silently drops the leading zero.
- Don't confuse the MICR line order. On a check the routing number is printed between ⑆ transit symbols; the account number and check number follow.
- Use the official directory for bank names. A passing checksum is a typo filter, not proof that the bank exists.
Frequently asked questions
How is a routing number checksum calculated?
Multiply the nine digits by the repeating weights 3, 7, 1, 3, 7, 1, 3, 7, 1 and add the results: 3×(d1+d4+d7) + 7×(d2+d5+d8) + (d3+d6+d9). The routing number is valid only if that total is a multiple of 10. The ninth digit is the check digit chosen to make this true.
Does a valid checksum mean the bank exists?
No. The checksum only catches typing mistakes such as a single wrong digit and most swapped neighboring digits. A number can pass the check and still not be assigned to any bank, or belong to a different bank than you expect. Confirm with the bank or your payment provider before sending money.
What do the first two digits of a routing number mean?
They show the Federal Reserve district and the institution type. 01–12 are the 12 Federal Reserve districts for banks, 21–32 are the same districts for thrift institutions (add 20), 61–72 are electronic-only numbers (add 60), 00 is the US Government and 80 is for traveler's checks. Other prefixes are not valid.
Which Federal Reserve districts are there?
There are 12: 1 Boston, 2 New York, 3 Philadelphia, 4 Cleveland, 5 Richmond, 6 Atlanta, 7 Chicago, 8 St. Louis, 9 Minneapolis, 10 Kansas City, 11 Dallas and 12 San Francisco. Each also has a letter from A to L, printed on paper currency.
Where do I find my routing number?
On a US personal check it is the 9-digit number printed first at the bottom left, before the account number. It is also in your online banking app or on the bank's website. Some banks use a different routing number for wire transfers than for ACH direct deposits.
Can this tool tell me the bank name?
No. Bank names come from the official routing number directory, which this offline tool does not include. It checks the structure and checksum and identifies the Federal Reserve district from the prefix, without sending your number anywhere.
Is it safe to enter my routing number here?
Yes. All checks run in your browser and nothing is uploaded or stored. A routing number identifies a bank, not your account, but the tool never asks for an account number.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.