U.S. Routing Number Validator Tool
🔒 No data is stored or logged. Validation happens in your browser.
What to Do Next
- ✓ Double-check the account number matches this routing number
- ✓ Confirm the bank name matches your recipient’s bank
- ✓ Verify the transfer type (ACH, wire, direct deposit) is supported
- ✓ Keep a record of this validation for your transaction
How Our Routing Number Validator Works
U.S. routing numbers use a checksum algorithm called the ABA routing number formula. Every valid routing number must pass this mathematical test, which banks designed to catch typos before money moves.
ABA Checksum Formula:
(3 × d₁ + 7 × d₂ + 1 × d₃ + 3 × d₄ + 7 × d₅ + 1 × d₆ + 3 × d₇ + 7 × d₈ + 1 × d₉) mod 10 = 0
The first two digits identify the Federal Reserve district where the bank is located. The next two digits pinpoint the specific Federal Reserve Bank. The fifth through eighth digits are the bank’s unique identifier. The ninth digit is the checksum that makes the whole thing work.
When you type a routing number, our validator tool multiplies each digit by 3, 7, or 1 in a specific pattern, adds them all up, and checks if the total is divisible by 10. If it is, the math checks out.
What Each Part of Your Routing Number Means
| Position | Purpose | Example (021000021) |
|---|---|---|
| Digits 1-2 | Federal Reserve District | 02 (New York) |
| Digits 3-4 | Federal Reserve Bank | 10 (Fed processing center) |
| Digits 5-8 | Bank Identifier | 0002 (Unique to the bank) |
| Digit 9 | Checksum | 1 (Validation digit) |
Who Needs This Routing Number Tool?
Anyone sending money in the U.S. If you’re setting up direct deposit, paying a contractor via ACH, wiring money to a vendor, or adding a new bank account to your payment app, you need to get this number right.
💡 Quick Tip
Banks sometimes have multiple routing numbers for different purposes (paper checks vs. electronic transfers vs. wire transfers). Make sure you’re using the right one for your specific transaction type.
What Happens If the Number Is Invalid?
If the checksum fails, you’ve definitely got a typo. Go back to your source (the bottom of a check, your bank’s website, or the recipient’s email) and compare digit by digit.
When Should You Validate a Routing Number?
Before every new payment setup. That includes adding a bank account to PayPal, Venmo, or Cash App, setting up autopay for bills, entering direct deposit info with a new employer, or initiating a wire transfer.
Quick Sanity Check: Sample Routing Numbers
| Routing Number | Bank Example | Valid? |
|---|---|---|
| 021000021 | JPMorgan Chase (NY) | ✓ Valid |
| 026009593 | Bank of America (NY) | ✓ Valid |
| 123456789 | Sample/Test | ✗ Invalid |
Frequently Asked Questions
Can a routing number change after I’ve set it up?
Yes. When banks merge or reorganize, they sometimes migrate accounts to new routing numbers. Your bank should notify you in advance, but it’s smart to verify before making important transfers.
Is it safe to share my routing number?
Sharing your routing number alone is generally safe because it just identifies your bank, not your specific account. However, someone needs both your routing number and account number to initiate transactions.
Do credit unions have routing numbers?
Yes. Credit unions use the same 9-digit routing number system as banks. The format and validation process is identical.
What happens if I use the wrong routing number?
If the routing number is invalid, the transaction will usually be rejected immediately. If it’s valid but belongs to the wrong bank, your payment might get delayed or bounced back.