A bank routing number typically isn't enough to gain access to your checking account, but someone may be able to steal money from your account if they have both your routing number and account number. Someone may also steal money using your debit card credentials. If you think your account has been compromised, you should contact your bank as soon as possible to minimize your liability.
TL;DR (Too Long; Didn't Read)
Generally speaking, a thief will need more than just your check routing number to gain access to your checking account. However, the odds of theft increase when the perpetrator has access to your routing number and checking account number.
Routing and Account Numbers
Bank routing numbers are nine-digit identification numbers for banks issued by the American Bankers Association. Some banks may have multiple routing numbers, such as for branches in different states.
Checks typically have the routing number for your bank and your account number printed on them. This information is used to cash or deposit checks. You also typically provide your routing and account numbers to people who need to transfer money in or out of your account, such as for the direct deposit of paychecks, Social Security payments or utility payments.
If someone just has your routing number, that's not enough information to transfer money from your account, since many people with accounts at your bank will have that same routing number. But if someone has your routing number and account number, they can impersonate you and potentially take money from your account without permission.
It's a good idea to avoid giving out your routing and account numbers to people and organizations that don't need them, and to only enter them on computers and phones you trust to be secure, since hackers and malware can eavesdrop on your typing to steal these numbers and, potentially, your money.
Debit Card Numbers
If you have a debit card associated with your checking account, its number can also be used to make purchases online. If someone steals your debit card number, especially if they get ahold of other information associated with the card such as its expiration date and security code, they can use this information to steal your money.
As with your bank account and routing numbers, it's a good idea to keep your debit card number safe by disclosing it only when necessary to make a purchase with an organization you trust.
If You Suspect Fraud
If you think there has been fraud on your bank account or your account or card number has somehow been compromised, it's a good idea to contact your bank immediately.
If your debit card or its PIN is compromised, and you notify the bank within two days, you legally can't be held liable for more than $50 in unauthorized transactions. If you wait longer, you could be liable for up to $500 in transactions.
If your account is otherwise compromised, you should notify your bank within 60 days, or you could be held liable for unauthorized transactions between the end of the 60-day period and when you notify the bank. Generally, the bank has a limited time under the law to investigate the issue depending on the exact circumstances, and if it can't complete its investigation fast enough, must at least issue you a temporary credit for the missing funds, minus a maximum of $50.
- Comptroller of the Currency Administrator of National Banks: Forgery and Fraud
- Splinter: Someone Can Empty Your Bank Account with the Information on the Front of Every Check you Write
- Detroit Free Press: Scam alert: Is Someone Using your Bank Account to Pay Their Bills?
- Bank of America: ABA Routing Number FAQs
- Washington Post: The Debit Card Nightmare: A Number is Stolen and Charges Pile Up
- CFPB: Bank Accounts and Services