# Patents Act 1977, Section 21: Observations by third party on patentability.


(1) Where an application for a patent has been published but a patent has not been granted to the applicant, any other person may make observations in writing to the comptroller on the question whether the invention is a patentable invention, stating reasons for the observations, and the comptroller shall consider the observations in accordance with rules.
(2) It is hereby declared that a person does not become a party to any proceedings under this Act before the comptroller by reason only that he makes observations under this section.

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Source: https://www.legislation.gov.uk/ukpga/1977/37/section/21 (the official version)
Page: https://openlegislation.uk/patents-act-1977/section-21
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.