Further to the article which was posted last month in which we advised that the UK’s membership of the PCT will be extended to include the Bailiwick of Guernsey, we have now ascertained that the date of coming into force of this provision will be 23rd March 2021 and not 1st January 2021.   Whilst the local legislation in Guernsey specified the date of 1st January 2021, it now appears that the extension will not formally come into effect until 23rd March 2021.

In consequence, any new PCT applications that are filed on or after 23rd March 2021 and which designate the UK will automatically also cover the Bailiwick of Guernsey. This means that, if/when a patent is subsequently granted in the UK deriving from such a PCT application, protection will automatically be afforded in Guernsey, without the need for applicants to reregister their UK patent in Guernsey. This change also means that residents and businesses located in Guernsey will be able to file new PCT applications with the UK Intellectual Property Office, the European Patent Office, or directly with the International Bureau.


For the avoidance of doubt, since the above provisions only apply to PCT applications filed on or after 23rd March 2021, any existing Guernsey patents or pending Guernsey patent applications should still be renewed in the usual way, if required.

For more information please contact the author, Louise Audhlam-Gardiner, at louise@lysaght.co.uk