Countries routinely sign bilateral and multilateral treaties that oblige them to abide by their terms.Ratification of the international treaty requires that common law countries should incorporate the treaty into domestic law. English common law serves as the foundation for Pakistan's legislation governing the reception of international treaties. The rationale of the common law system typically does not directly incorporate international treaties but requires separate enabling legislation so that there should be no conflicting legal provisions between national law and the provisions of the relevant treaty. The rationale behind incorporation varies as per constitutional requirements and the interest of the state. This paper provides the general explanations in the context of the common law legal system specific to Pakistan; as a case study, international space law treaties have been discussed to provide the answer to why incorporation and implementation is an important steps.