To ensure the goods may travel with the minimum of interface en-route and yet offer safeguards to Customs administrations in all transit , the TIR system contains four basic requirements :-
----- That goods should travel in secure vehicle or containers .
----- That duties and taxes at risk should throughout the journey be covered by an internationally valid guarantee .
----- That goods should be accompanied by an internationally accepted carnet taken into use in the country of departure and serving as control document in the countries of dispatch , transit and destination .
----- That Customs control measures taken in the country of departure should be accepted by the countries of transit and destination .
The TIR convention provides that goods shall be carried in containers or in vehicle whose load compartment is so constructed that there shall be no access to the interior when secured by Customs seal and that the result of any tempering will be clearly visible . The Convention sets out standards of constructions and approval procedures and goods may only be carried under cover of a TIR carrnet in approved vehicles and containers . Special provisions apply for heavy and bulky goods which can not be carried in normal transport.