Bond-based clearance authorisation permits conditional import or export when preconditions would cause detriment, subject to timely compliance. Assistant or Deputy Commissioners of Customs may permit import, export or clearance despite required preconditions by accepting a bond with specified amount, surety or security and conditions including a time for completing the required act; timely performance mandates cancellation and return of the bond and avoidance of penalties, while failure to perform permits proceeding on the bond and other lawful actions.