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It is not possible to obtain a granted “international” or “worldwide” patent. The Patent Co-operation Treaty (PCT) is a system whereby you can effectively “reserve the right” to file an application in over 150 countries. A current list of the PCT states can be viewed at

Whilst an International (PCT) patent application covers a large number of countries, there are still some countries which are not included and so it is important to bear this in mind when considering your filing strategy. A PCT patent application can be filed with the UK Intellectual Property Office (UKIPO), the European Patent Office (EPO) or the World Intellectual Property Organisation (WIPO).


A PCT application is filed and initially prosecuted as single application, potentially offering protection in over 150 contracting states. The application is published soon after 18 months from filing (or the earliest priority date where applicable), is searched and a Written Opinion is issued. This provides an early indication of the patentability of your invention and any objections that the application is likely to face. It is also possible to request further examination of your application, which gives you the opportunity to argue in support of your application. Examination is optional and we are able to advise the best strategy for prosecution of your application considering the costs involved.

At either 30 or 31 months from the filing date (or the earliest priority date where applicable) of your PCT application it is necessary “to enter the national/regional phase”. This means that you need to convert the PCT application into separate patent applications in each territory of interest to you. For example, if you wish to seek protection in China and US, you will need to pay the application fees and submit your PCT application to the Chinese and US Patent Offices. A significant advantage of the PCT system is that the costs of filing separate foreign patent applications are delayed for 2½ years from the priority date, allowing you more time to assess the financial viability of your invention. You are also given an early indication of the patentability of your invention in the Written Opinion. However, the PCT application is not granted as a single International Patent and you will have to pay the fees and file separate foreign application in each territory of interest to you.

We are able to provide costs estimates and prosecute a PCT patent application on your behalf. Please give us a call if you wish to discuss this further.


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