Post-grant opposition

The patent is granted. You would like to believe that is the end of the argument. For twelve months, it is not.

In simple words

An opposition filed by a person interested at any time after grant but before twelve months from the date of publication of the grant, decided by the Controller with the assistance of an Opposition Board.

Think of it as

A one-year window in which the grant can still be unpicked.

Why it matters

Unlike pre-grant opposition, only a person interested can file, the procedure is fuller, and an Opposition Board of three examiners examines the grounds and makes a recommendation. It is the most structured way of attacking a patent short of revocation proceedings before a High Court.

A simple example

A competitor with a product in the same field files within twelve months of the grant publication, raising prior publication and section 3(d). The Board reports on each ground and recommends; the Controller then decides.

Common mistake

Counting the twelve months from the date of grant rather than from the date the grant was published.

Where it comes from

Patents Act 1970, section 25(2); Patents Rules 2003, rules 55A to 63