A bank account number on a check is typically 8 to 12 digits long, though some banks use as few as 5 digits or as many as 17. The exact length depends on your bank’s numbering system, so there is no single universal standard.
Where to Find the Account Number on a Check
The bottom of every check has a line of numbers printed in a special magnetic ink. This line contains three pieces of information, read left to right: the routing number, your account number, and the check number. The routing number is always exactly nine digits and identifies your bank. The account number, which comes next, identifies your specific account at that bank. The check number (sometimes called the serial number) matches the number printed in the upper right corner of the check.
Small symbols separate these three groups of numbers. You’ll see characters that look like vertical lines or colons between each section. If you’re having trouble telling where the routing number ends and the account number begins, count nine digits from the left. Everything after that separator, up to the next symbol, is your account number.
Why Account Number Length Varies
Each bank assigns account numbers using its own internal system, which is why there’s no fixed length across the industry. Most fall in the 8 to 12 digit range, but shorter and longer numbers exist. A small community bank might use shorter numbers simply because it has fewer accounts to track, while a large national bank with tens of millions of customers may need longer strings to keep every account unique.
Your checking and savings accounts at the same bank will have different account numbers, even though both may be the same length. If you hold multiple accounts, double-check that you’re reading the number for the correct one before entering it anywhere.
Leading Zeros Matter
If your account number starts with one or more zeros, include them. A 10-digit account number that begins with “00” is not the same as the 8-digit number you’d get by dropping those zeros. When you set up direct deposit, pay bills online, or link your bank account to a payment app, entering the full number with leading zeros is essential. Leaving them off can cause a transaction to fail or, worse, route money to the wrong account.
How to Confirm Your Account Number
Reading the number off a check is the most common method, but it’s not the only one. You can also find your account number by logging into your bank’s website or mobile app, where it’s usually listed under account details. Your monthly bank statement will show it as well, typically near the top of the first page. If you’re still unsure, calling your bank’s customer service line and verifying your identity will get you the number directly.
When you need your account number for a form or online setup, it’s worth cross-referencing at least two sources. Comparing the number on your check to the one in your online banking portal takes only a moment and can save you the hassle of a rejected transaction.
Account Number vs. Routing Number
People often confuse these two because they sit right next to each other on the check. The routing number (always nine digits) identifies the bank itself. Every customer at the same bank in the same region shares that routing number. Your account number is unique to you and points to your individual account. Both are needed for electronic transfers like direct deposit and ACH payments, so you’ll usually be asked to provide them as a pair.
The check number, the shortest group on that bottom line, is only used to identify that specific check. You won’t need it for setting up transfers or linking accounts.