ACH fraud is not that simple to detect or revert. How soon would you know if $500 exited your checking account? If it's a small-business account, with most bank

ACH fraud is not that simple to detect or revert. How soon would you know if $500 exited your checking account? If it's a small-business account, with most banks, you have 24 hours to report each debit that you want reversed. If it's a personal account, you may have up to a month. But the same merchant account can debit your account again, even while you are reversing their previous debits. You can't block them with a personal or basic small-business account, you have to upgrade to an account that you always keep $100K in. The banks' suggestion? Close the account, open a new one, and never give anyone the account and routing numbers. Never write a check from that account. Use the bank's web site to initiate bill payments – they'll get checks from the bank's account.