Finding the routing number on a check
The bottom edge of every paper check uses a stylized font called MICR. Here is how to read it and identify the routing number, account number, and check number at a glance.
The MICR line
Every US paper check carries a row of numbers along its bottom edge, printed in a distinctive blocky font called MICR E-13B. MICR stands for Magnetic Ink Character Recognition; the ink contains iron oxide so that high-speed sorting machines at processing centers can read the characters magnetically rather than visually. The font has fewer than 20 characters total — the digits 0–9 and a few control symbols.
The MICR line is divided into three to four groups, separated by special control characters:
- Routing number — the leftmost group, always exactly nine digits, bracketed by transit symbols (the symbol that looks like ⑈).
- Account number — the middle group, varying in length from bank to bank but typically 7–14 digits.
- Check number — the rightmost group, matching the small check number printed in the top-right corner of the check.
- Amount field — sometimes appears at the far right, but is left blank on personal checks and added by the depositing bank during processing.
Distinguishing routing from account
The two easiest ways to tell the routing number apart from the account number on a check:
- The routing number is always exactly nine digits. If you count nine digits from the leftmost transit symbol, that's the routing number.
- The routing number is identical on every check in your checkbook, while the check number changes by one with each check. The account number is also constant, but it's in the middle position rather than the leftmost.
What about printed-on-demand checks and remote deposit?
Online banking platforms that issue checks through bill-pay don't physically print MICR lines; they typically send an ACH credit instead. If a check arrives in the mail with an obviously laser-printed MICR line, it's a "convenience check" generated by your bank's bill-pay system and is functionally equivalent to a physical paper check.
Remote deposit capture (taking a photo of a check with your phone) reads the MICR line via OCR rather than magnetically, but the same nine-digit routing number applies — and the same restrictions on duplicate deposits apply, since the receiving bank software detects MICR-line repeats.
Counterfeit and altered checks
The MICR line is the most-counterfeited element of a US paper check. Fraudsters print fake checks with MICR lines that point to legitimate banks but credit accounts the fraudster controls. The receiving bank's software accepts the deposit (because the routing number is real), credits the customer's account provisionally, and only discovers the fraud days later when the check bounces from the originating bank. By then, the fraudster has typically convinced the customer to wire the "overpayment" elsewhere. If you are ever asked to deposit a check and then send back part of the funds by wire, gift card, or cryptocurrency, it is a scam — every time, without exception.