Shipping companies are required to "block" packages in which a Specially Designated National ("SDN") or other blocked person has an interest. When a package is required to be "blocked," the shipper must retain the package rather than reject and return it to the sender. Blocking is not required if a general or specific license from OFAC authorizes the shipper to reject or process the package, or if the transaction is otherwise exempted from the prohibitions based on the type or content of the package. To request a license for the package’s release, apply online or send a letter with a detailed description of the package’s contents and an explanation of the parties involved in the transaction, along with a copy of the package’s air waybill or Customs Declaration and Dispatch form, to:
U.S. Department of the Treasury
Office of Foreign Assets Control
Licensing Division
1500 Pennsylvania Avenue, NW
Washington, DC 20220