Patent amendment proceedings
Patent amendment proceedings

The following IP guidance note provides comprehensive and up to date legal information covering:

  • Patent amendment proceedings
  • When is patent amendment permitted?
  • What amendments are permitted?
  • Practicalities of formulating amendments
  • Post-grant amendment—comptroller's general power to amend
  • Post-grant amendment—PA 1977, s 75 amendment
  • Stages in amendment applications
  • Discretion in response to behaviour of person applying for amendment
  • Conditional or unconditional amendment request?
  • Amendment to deal with errors in the specification
  • more

There are several different ways to amend a patent, at various stages of its life, and depending on whether the application for the patent originated in the UK Intellectual Property Office (UK IPO), the European Patent Office (EPO) or under the international Patent Co-operation Treaty (PCT) system.

However, patent amendment is not freely allowable because this would mean the goalposts shifting on where the boundaries of the patent owner's monopoly rights lie. This is not acceptable in a patent system where the owner has exclusive or so-called 'monopoly' rights, since the public accessing the register of those rights must be able to determine whether or not they might infringe the patent, without the patent changing its nature over time.

On the other hand, it is not possible to definitively know at the time of applying for a patent, the existence of every possible piece of prior art, for example. So if prior art comes to light later, it should be possible to amend the patent so as to carve out of the patent and disclaim what has subsequently been found to be prior art (which would otherwise destroy the novelty or inventiveness of the claims in the patent). This kind of amendment will generally be allowed. What is not allowed is for an amendment to result in broadening the patent claims. Even if