Diputs - just for clarification, are the funds actually coming out of (or in to) an account with your bank? Or are these cash payments directly from the customer to the contractor and don't involve your bank? I just wasn't sure from your post. If the funds involve your bank and there's evidence of structuring, then yes I agree file a SAR on the customer as Doug states. But if this is just based upon having knowledge that the customer is paying the contractor in amounts under 10k (cash not involved with the bank), I don't know that a SAR would be appropriate because you have no actual knowledge or information of payments, withdrawals, etc, and there's no transaction conducted through the bank.