If we decide not to open a deposit account based on some comments that the potential customer made (comments make us suspicious of the source of the funds she will be depositing), do we need to send out a letter or can we just tell her we are not opening the account? I know if we deny the account based on information we received from chexsystem we need to send an adverse action notice but there is nothing in the chexsystem report that would cause us to deny. Thanks!

No, if you don't open the account, just tell them something along the lines of, "thank you for your interest, but it doesn't look like we'll be able to accommodate your needs...".