OFAC Attorney: One of the most important things to do is to determine whether you must block or reject the transaction. That’s important because blocking requires the person to hold the property and not let it transfer anywhere, including not letting the property go back to the originator. Rejection would involve not engaging in a particular transaction and sending the property back to the originator. Determining the proper response is very important. Then, you must determine whether or not you need to file a report with OFAC describing the rejected transaction or blocked property.