If you have a granted patent for a product, you can mark that product as patented. You can only mark your product as patented if the patent for that product has been granted.
Marking a product as 'patent applied for' when this is not true, or marking an unpatented product as patented, is a criminal offence, with the risk of prosecution. Read about marking patented products. Even if your product is not marked, you can still take legal action for infringement.
Infringement of patent
Infringing a patent means manufacturing, using, selling or importing a patented product or process without the patent owner's permission.
If someone infringes your patent, you can try to settle the dispute with them outside of court, or take legal action and claim damages against them. See resolving patent disputes.
If litigation is the only way to deal with infringement, you'll probably need professional advice. You can search for a registered patent attorney UK-wide or find a patent attorney in Northern Ireland.
What if you infringe someone's patent rights?
You must make every effort to respect other people's patents or you could face legal action and possibly damages.
If you have infringed someone else's patent and they intend to sue you for patent infringement, you might want to try to negotiate a settlement with them. You should get professional advice from a patent attorney or solicitor.
If someone does sue you for infringement, but you think that you have not infringed their patent, you will have to prove that your idea is significantly different from theirs.
There may also be a case if their patent claim is invalid, in which case you can take legal action to challenge the validity of their patent, or their patent claim. If you win this action, their patent could be cancelled, but you should bear in mind that if you lose, you will probably have to pay the other side's costs.
The Intellectual Property Office (IPO) can conduct a patent check for documents that you can use to challenge a patent. See IPO's guidance on patent infringements.
Patent protection abroad
A UK patent only protects you in the UK. To protect your invention in other countries you will need a patent in those countries. Otherwise, anyone can legally make, sell or use your invention abroad. For more information, see how to protect intellectual property abroad.
Requesting an opinion
If you become involved in a dispute about infringement or the validity of your patent, you can ask the IPO for an impartial opinion, for a fee. See more on patent protection and infringement. If you don't agree with an opinion given by the IPO you can ask them to review it. Read about objecting to patent applications.
Resolving patent disputes
If someone uses your patent without permission, there are various ways to stop them. For more information, see resolving patent disputes.