Common Routing Number Errors and How to Fix Them

The routing number must be exactly 9 digits. The most frequent cause of length errors is copying only part of the MICR line from a check — accidentally including a boundary symbol as a digit, or misreading the boundary between the routing number and account number.

An 8-digit input almost always means the leading zero was dropped. Some routing numbers begin with 0 — for example, 071000013 for US Bank. If you are copy-pasting from a source that stripped leading zeros, add the leading zero back.

A 10-digit input usually means one digit from the account number was included. On the MICR line, routing and account numbers are adjacent — without the boundary symbols it is easy to grab one extra digit.

The ABA 3-7-1 checksum catches most single-digit transcription errors. If you enter a routing number with the correct 9-digit length but the checksum fails, one digit is almost certainly wrong. Common patterns include transposing two adjacent digits (e.g., 123 → 132), misreading a 6 as an 8, or duplicating a neighboring digit.

If the checksum fails, do not guess or try variations. Obtain the correct routing number directly from the bank — either from their website, from a check, or by calling customer service.

Note that passing the checksum does not confirm the routing number routes to the correct bank — it only confirms the number is structurally valid. A routing number from a bank that has since been acquired or closed may still pass the checksum but route incorrectly.

Large US banks maintain separate routing numbers for checks, ACH transactions, and wire transfers. Using the check routing number for an ACH direct deposit will often work, but using it for a wire transfer may fail. Many banks have specific wire routing numbers that differ from their ACH numbers.

International wire transfers additionally require SWIFT BIC codes. If you are wiring funds internationally, confirm with your bank whether a routing number or SWIFT BIC is required — and get both if possible.

When in doubt, call your bank and ask specifically: 'What is the routing number for incoming ACH / domestic wire / international wire payments?' This 30-second call prevents the most common cause of misdirected transfers.