Opposition, Revocation and Amendment After Grant
There are no provisions for formal opposition by third
parties to a British national patent application while it is pending.
However, once the application has been published, third
parties can comment to the Patent Office about the patentability of the
invention, and the examiner will take their comments into account during
After grant, third parties can apply to have the patent
revoked if they have good grounds for doing so, such as knowledge of prior
art which was not available the examiner (including, for example,
knowledge of disclosure of the invention by the applicant before the
application was filed). The result of revocation proceedings might be that
the patent is maintained, that it is revoked entirely, or that the scope
of the claims in the patent is reduced.
If the patentee becomes aware, after grant, of prior
art which affects the validity of the patent, the patentee can voluntarily
apply to amend the patent. Any such amendment must not add any new
technical information to the patent specification, and it must not
increase the scope of the patent.
If a patentee becomes aware of invalidity of the
patent, it is important to try to put the matter right without delay and
not to try to enforce the invalid patent, otherwise difficulties can
subsequently be encountered in amending the patent and enforcing it.