The different routes you can take to patent an invention are the national, the regional, or the international route. Each option has its advantages and the best solution for you will depend on your invention and the markets your company operates in.

An international application is a useful way to apply for patents in a number of different countries simultaneously and protect those important export markets.

An international patent application could be filed with your National Patent Office, or directly with the International Bureau of WIPO if permitted by the national security provisions in your national law. Both Offices may act as PCT "Receiving Offices".
 For more information, see Filing

Detailed information about international patents and the PCT system is available from the World Intellectual Property Organisation (WIPO) website - PCT Resources.