Cookies on Pinsent Masons website

Our website uses cookies and similar technologies to allow us to promote our services and enhance your browsing experience. If you continue to use our website you agree to our use of cookies.

To understand more about how we use cookies, or for information on how to change your cookie settings, please see our Cookie Policy.

Defences against patent infringement

Businesses can face claims of patent infringement if they carry out acts infringing patented products or processes without the consent of patent rights holders. However, UK patent law contains a number of defences against infringement which businesses may be able to rely on to defeat such claims.

This guide is based on UK law. It was last updated in August 2018.

Statutory defences

An act which would otherwise infringe will not do so if it is done for the following purposes:

Private Use – it is done privately and for non-commercial purposes – there cannot be any element of commercial purpose involved. 

Experimental Use – the act is done for experimental purposes relating to the subject matter of the invention, this includes experiments that are performed to further scientific knowledge and anything done in or for the purposes of a medicinal product assessment, including clinical trials and other studies required for obtaining or varying an authorisation to sell or supply, or offer to sell or supply, a medicinal product in the UK or elsewhere. 

Extemporaneous preparation of prescription – the preparation of a medicament in a pharmacy for an individual in accordance with a prescription.

Vessels and Aircraft – the use of the product or process on a ship or aircraft which is temporarily in the airspace or waters of the UK.

Agricultural – the use in specified circumstances by a farmer of the product of their harvest, under section 60 (5)(g) of the Patents Act 1977,  or the use of breeding stock or other animal reproductive material constituting or containing the patented invention sold to the farmer by the patentee or with his consent, for agricultural purposes, under section 60(5)(h).

Studies, tests or trials – the act is done in conducting a study, test or trial which is necessary for the application of paragraphs 1 to 5 of Article 13 of the EU Directive of 2001 on veterinary medicinal products or paragraphs 1 to 4 of Article 10 of the EU Directive of 2001 on medicinal products for human use or any other act which is required for the purpose of the application of those paragraphs.

Prior Use - Under section 64 of the Patents Act 1977 if a person in the UK before the priority date of the patent did, in good faith, an act which would constitute infringement of the patent if it were in force, or makes serious preparations to do such an act, then that person has the right to continue to do that act, though they are not permitted to grant a licence to others to do so. If this was done in the course of business then that person is entitled to authorise other members of his or her business to do the act and also to assign the right to do the act to anyone who acquires that element of his or her business.

Non-statutory defences

Beyond statutory rights there are also other defences to patent infringement which could apply:

Invalidity – a party cannot be held to have infringed a patent that is not valid, therefore often a party alleged to infringe a patent will respond with a counterclaim that the patent in question is invalid and should be revoked.

Exhaustion – once a patentee has dealt in or consented to dealings in goods within the EEA that otherwise would infringe their patent rights, those rights are said to be exhausted. This means that they cannot prevent further circulation of those goods within the EEA, for example via importation into the UK which otherwise would be an infringing act. What the position on exhaustion of rights-based defences will be post-Brexit has yet to be determined.

Abuse of a dominant position – whilst it is established that the existence of a patent right per se cannot be considered to be an abuse of dominant position under EU competition rules contained in Article 102 of the Treaty on the Functioning of the EU, it has been held that the way in which a patent right is exercised could be considered to be abusive. It has also been held that there could be a defence to infringement where the enforcement of the right assists the patentee in conduct which would be considered abusive under Article 102.

'Gillette defence' – As discussed above it is not possible to be infringe a patent which is invalid. In Gillette Safety Razor co v Anglo American Trading Co, the defendant successfully argued that the 'infringing' act complained of was actually disclosed in a prior art document. As there was no substantial difference between the prior art and the actions of the defendant the court held that this was a good defence. It should be noted that this case was decided in 1913 and, whilst still technically good law, recent commentary would suggest that in actual fact this is not really a separate defence to infringement, rather an obviousness attack on the validity of the patent.       

Compulsory licences

Compulsory licences are provided for in section 48 of the Patents Act 1977. 

In certain circumstances, any person may apply to the UK's comptroller general of patents, designs and trade marks: 

  • for a licence under the patent;
  • for an entry to be made in the register to the effect that licences under the patent are to be available as of right; or
  • where the applicant is a government department, for the grant to any person specified in the application of a licence under the patent.

These compulsory licences can be applied for at any time after the expiry of three years, or other prescribed period, from the date of the grant of a patent, and where relevant grounds are met. These grounds include: 

  • where demand for a product is not being met in the UK;
  • the patentee has refused to grant licences on reasonable terms for the exploitation of an invention which is a technical advance of considerable economic significance.