The Patent Cooperation Treaty, known in short as PCT, was established in 1970 by several member states as an international law treaty to provide a unified manner for patent application filing. The Patent Cooperation Treaty also endeavours to protect patented inventions in the member countries. When you file a patent application under the Patent Cooperation Treaty it stands known as the PCT or international application. By means of the PCT it is possible to file one application at a relevant Receiving Office and you can also do so in a single rather than multiple languages.

Once the application is filed, the International Searching Authority will then conduct a patent search, which can be optionally followed up by means of a preliminary assessment done by another international body. The authority is known as the IPEA, which stands for International Preliminary Examining Authority.The last step in the process involves administering of the application by the relevant national authorities. The authorities do thus provide the granting of the patent. Member countries make up the Paris Union.

Originally the PCT only existed of 18 member states, but contracting members have grown since then. If a country is a member to the Paris Convention, it can also become a member of the PCT. Most of the countries in the world are member signatories to it, with some 142 member states in 2009.

Known as the international procedure, the Paris Cooperation Treaty procedure helps to reduce the costs of patent filing in numerous countries and it ensures that a specific standard for filing is adhered to. There are two phases in the process, involving the initial international stage and the national stage. When doing a PCT filing, you will have to make use of an intellectual property attorney.