Hello! Our client has ACH info on file with us for his monthly fees. We have been using the same info for the last 12 months when POOF! It all of a sudden stopped working in September. He states that nothing has changed with the bank and that other companies have withdrawn from his account for whatever needs he has with them. When I ran his ACH info today, just to try it again, it gave "The transaction was declined because the bank account is incorrect, or there is a security concern." What would the security concern be? And why would it fail all of a sudden after working fine for 12 months? He swears up and down that nothing is different, and he has been in contact with his bank who has said that they didn't even see an attempt from us to withdraw. 

Any ideas?