The international patent application (PCT) offers a period of 30 months to decide in which countries patent protection is sought for an invention.

With a PCT application, the applicant obtains an option for patent protection in many countries.

The international phase begins with formal filing with the USPTO, EPO, or WIPO.

A search authority prepares a report on novelty and inventive step.

The international application is published after 18 months; if the search report is not completed by that time, it is published later.

The applicant may also request an international preliminary examination to obtain a preliminary assessment from an authority.

The international phase does not create a global patent, but only extends the decision period for initiating national procedures.

After 30 months, the application must enter the national phase, otherwise the patent expires in the country concerned.

The transition to national procedures initially incurs high translation and representation costs.

In the national phase, each country decides independently on whether to grant or reject the patent.

All patents from a PCT application have the same filing date, but depending on the respective application procedures, they have an independent fate.

Annual fees and national decisions in nullity proceedings lead to differences in the validity of individual patents that have emerged from the same PCT application.

An international application can claim the priority right of an earlier national application; this priority right then also applies to subsequent applications.

The first page of an international patent application contains information on the filing date, number, and file number, as well as any priority rights that may exist.