Understanding routing number validation

Last updated: September 25, 2026

A Routing Number field always checks what an employee types. Whether a failed check stops them from submitting is your decision — one checkbox on the field.

What it is

The Routing Number field type does two separate things with the nine digits an employee enters, and they're easy to confuse.

It validates the number arithmetically. Onboarded runs the U.S. ABA check — digit count, an allocated Federal Reserve prefix, and the standard checksum. No lookup, no list.
It looks the number up to name the bank. Once the number passes, Onboarded checks it against a routing number directory sourced from FedACH and shows the institution back to the employee as confirmation.

If you remember nothing else: the arithmetic check can block a submission. The bank lookup never can.

Why it matters

Direct deposit is usually the last thing standing between a new hire and their first paycheck, so a form that rejects a real routing number turns into a support call fast — and a form that accepts a typo turns into a failed payment two weeks later.

Knowing which of the two checks fired tells you which one to go change. Most reports of "the form won't let me submit my routing number" come down to the setting below, not the directory.

How it works

The ABA check

A value passes when all three of these hold:

It's exactly nine digits.
The first two digits fall in a range the Federal Reserve has allocated — 00–12, 21–32, 61–72, or 80.
The weighted checksum divides evenly by ten. Weights run 3, 7, 1 across the nine digits, so 3(d1+d4+d7) + 7(d2+d5+d8) + (d3+d6+d9) ends in a zero.

This is pure arithmetic, which is why a brand-new routing number issued last month still passes. It runs on every entry no matter how the field is configured, and it runs again on the server when the form is submitted, so the two can't drift apart.

The setting that decides whether a failure blocks

Open the field settings on a Routing Number field and you'll find Required validations with a single checkbox, U.S. ABA Number.

Checked — a value that fails the ABA check is rejected as invalid and the employee can't submit until they fix it. New Routing Number fields start here.
Unchecked — the check still runs, but a failure is advisory. The employee sees a notice and submits anyway.

The bank-name confirmation

After a number passes the ABA check, Onboarded looks it up in the directory. A hit shows a green check with the institution's name. A miss shows a grey line: We couldn't independently verify this routing number - You can still submit the form and continue with the process but please double check to make sure the number is correctly entered.

A miss is not a rejection. It means the number is arithmetically sound but isn't in the directory yet — common with small credit unions and recently merged institutions.

These two messages look similar and mean opposite things. "We couldn't independently verify this routing number" is advisory and the employee can continue. If employees are genuinely stuck, the value is failing the ABA check and U.S. ABA Number is checked on the field — that's the setting to revisit, not the directory.

Example

Take an account placing warehouse staff across three states. Employees bank with everything from national chains to two-branch credit unions, and the account keeps hearing that people can't finish their direct deposit form.

Two different things are happening. Employees at a small local credit union see the grey "couldn't independently verify" line, shrug, and submit — nothing to fix there. The ones who are actually blocked mistyped a digit, which broke the checksum, and U.S. ABA Number is checked on the field, so the form holds them there. That's the block working as intended: an account that would rather catch a typo up front than chase a returned ACH payment leaves the box checked.

An account that would rather never stop an employee mid-form clears the box instead, accepts the number as typed, and catches problems in payroll reconciliation.