Bank Routing Number Generator

The Bank Routing Number Generator produces random nine-digit numbers in the shape of a US ABA routing transit number, one to ten at a time. Type how many you want, press Generate, and each number appears on its own card. The numbers are made of random digits and are not tied to any bank, which makes them useful for filling a form field in a test environment and useless for anything else.

How it works

There is one setting, the count, which accepts 1 to 10 (default 5). Each number is built from three random pieces that mirror the layout of a real routing number: two digits for the Federal Reserve routing symbol, two digits for the reserve bank or processing center, and five more digits. The pieces are zero-padded so the result is always exactly nine characters long, for example 041523987 or 000073412.

What the tool does not do matters just as much. It does not compute the ABA check digit, and it does not restrict the first two digits to the ranges real banks use. So while every result looks like a routing number at a glance, most will fail a checksum validator. If your form validates routing numbers properly, this is the right tool for testing the "invalid number" path and the wrong one for the "valid number" path.

What a real routing number looks like

A US routing number is nine digits, and each part has a job:

• Digits 1–2: the Federal Reserve district. Real values are 00–12 for ordinary banks, 21–32 for thrift institutions, 61–72 for electronic-only routing, and 80 for traveler's checks. Anything else (13–20, 33–60, 73–79, 81–99) is not assigned.
• Digits 3–4: which Federal Reserve bank or check-processing center serves the institution.
• Digits 5–8: the institution's own identifier within that district.
• Digit 9: a check digit. Multiply the first eight digits by the weights 3, 7, 1, 3, 7, 1, 3, 7, add them up, and the ninth digit is whatever makes the total a multiple of 10.

Example with a real, widely published number: 021000021 (JPMorgan Chase, New York). 0×3 + 2×7 + 1×1 + 0×3 + 0×7 + 0×1 + 0×3 + 2×7 = 29, and 29 + 1 = 30, so the check digit 1 is correct. Run the same math on a generated number and roughly nine times out of ten it will not add up, and the first two digits will often fall outside the assigned ranges too.

Ways people use it

• Placeholder data in forms and mockups. A direct-deposit or ACH form needs something in the routing field for a screenshot or a demo. A random nine-digit string does the job without borrowing a real bank's number.
• Negative-path testing. Feed a batch of ten into a validator and confirm that malformed numbers are rejected with a sensible error.
• Seeding a test database. Ten at a time is enough for a fixtures file. Pair each one with a number from the Bank Account Number Generator to build a complete fake account record.
• Teaching the format. Generate a few and have students check them against the checksum rule above. Most will fail, which is the point of the exercise.

Routing number vs. account number

A lot of people arrive here looking for "routing and account number" together. This page only makes the routing half. The routing number identifies the bank; the account number (usually 8 to 12 digits in the US, though the length varies by bank) identifies your account at that bank. On a check, the routing number is the nine digits at bottom left between the ⑆ symbols, the account number follows it, and the check number comes last. For a fake account number use the account number tool; for card numbers that pass a Luhn check, the Random Credit Card Generator and Debit Card Generator are the right pages. All of these live under all developer & test data tools.

Sample output