Number of digits vary. The only thing set in stone is the ABA number of the bank, which is nine. For ex, at BofA, CA has 10 digits and WA (former Seafirst) has eight. Also, WA has same account number for checking and savings. The bank normalized all accounts to 12 digits, so WA accounts have four zeros at the beginning and CA accounts have two zeros at the beginning.
https://answers.yahoo.com/question/index?qid=20080311114854AAIhnQf
Note for California customers: If your account has check-writing capabilities and you opened the account in Southern California, you may see a different routing number on your checks than the number displayed above. You can use either number.
https://www.wellsfargo.com/help/routing-number/index
***Exception: If the Share ID for your Savings Account is 00, then the 10-digit account number begins with 98.***. Example 1: If your member account number is six digits (123456) and the Share ID is 00, your 10-digit account number would be 9800123456.
https://www.pscu.org/account-numbers/
Find Account and Routing Numbers. You can find your account number on your checks (see below) or in the top right corner of your statement, directly below the date range. Your routing number: You can find your routing number on your checks (see below) or by identifying the state where you opened your checking account.
https://www.chase.com/psmhelp/index.jsp?pg_name=shared/help/page/AccountNumber_hwtf
Securities and other investment and insurance products are: not a deposit; not FDIC insured; not insured by any federal government agency; not guaranteed by TD Bank, N.A. or any of its affiliates; and, may be subject to investment risk, including possible loss of value. ©2016 TD Bank, N.A. All Rights Reserved.
https://www.tdbank.com/tdhelps/default.aspx/what-is-my-account-number/v/37526333/
Your Wells Fargo EasyPay® Card routing number is: 031302777. Your routing number is: Your routing number is: Note for California customers: If you opened your account in Southern California, you may see a different routing number on your checks than the number displayed above. You can use either number. Note for California customers: If your account has check-writing capabilities and you opened the account in Southern California, you may see a different routing number on your checks than the number displayed above. 
https://www.wellsfargo.com/help/routing-number/index
The 10-digit account number is made up of the Share ID, zeros and your member account number. Example 1: If your member account number is six digits (123456) and the Share ID is 00, your 10-digit account number would be 9800123456. Example 2: If your member account number is five digits (12345) and the Share ID is 00, your 10-digit account number would be 9800012345. The 10-digit account number is made up of the Share ID, zeros and your member account number. Example 1: If your member account number is six digits (123456) and the Share ID is 01, your 10-digit account number would be 0100123456.
https://www.pscu.org/account-numbers/
It's on your checks on the bottom. There is a routing number, which will correspond to numbers written like a fraction usually printed on the upper right hand corner of the check, and then there will be the account number and your check number. Exclude the check number and you have your account number.
https://www.quora.com/How-do-I-find-my-Citibank-account-number
There is a number behind your ATM card for citibank helpline or u can get it online as well. That is a helpline number,call on that number and they will ask you some simple questions about your bank account and some of your personal details. please dont provide them your atm pin. thats it after answering them those questions they will provide you the number. Written Apr 29 · View Upvotes.
https://www.quora.com/How-do-I-find-my-Citibank-account-number
Your account number: You can find your account number on your checks (see below) or in the top right corner of your statement, directly below the date range. See your statements online.
https://www.chase.com/psmhelp/index.jsp?pg_name=shared/help/page/AccountNumber_hwtf
how many digits in account number
There are 10 digits in account number. There are 10 digits in an account number.