We often advise clients that any product made in accordance with their granted patent should be suitably marked as patented.  While there is no requirement for this in UK law, patent marking of products offers considerable benefits and safeguards.  On the other hand, there are potential downsides of patent marking and these might outweigh the advantages for some patent holders.

Here we explain the basic principles of patent marking, and we discuss some reasons why patent holders might (or might not) choose to mark their products as patented.

Why should patented products be marked?

Marking a product as patented puts all third parties “on notice” that relevant patent rights exist, thereby providing a deterrent against copying.

Crucially, patent marking gives the patent owner the best prospect of being awarded financial remedies in the event their patent is infringed.  This is because a patent infringer is not liable to pay damages if they are able to prove that they were not aware of the existence of the patent, and had no reasonable grounds for supposing that the patent existed, at the time of the infringement.  On the other hand, the infringer cannot rely on this argument to avoid paying damages if the product is properly marked as patented.

Patent marking is sometimes also used as a demonstration of innovation and technical prowess, thereby strengthening the product maker’s brand.

How should products be marked?

An effective patent marking on a product must include the word “patent” or “patented”, together with either the number of the patent or the address of a website which contains information about the patent.  The inclusion of the patent number or website is critical for establishing that other persons should be taken to be aware of the patent.

A QR code may additionally be included, but will not in itself provide notice of the relevant patent rights.

Since UK patent law refers to “application to a product” in regard to patent marking and the award of damages for infringement, it is safest to directly and permanently mark the product with the necessary patent details, for example by stamping, engraving or casting.

The “virtual marking” option requires that any referenced website must be accessible to the public free of charge.  The website must clearly associate the relevant patent number(s) with the product, and the product must be clearly identified, e.g.  by including any relevant model numbers and variants that exist.  Clear information on the website will give the patent owner the best chance of being awarded damages in any patent infringement proceedings.

Virtual marking allows for updates to be easily made when the status of the patent changes, due to revocation, lapse or expiration of the patent.  It is important for the patent owner to know that falsely representing an article as a patented product is a criminal offence, even where the false representation results from a change of status of a previously valid patent.

Rights holders should therefore ensure that any change of patent status is reflected in their patent markings; clearly, this is more easily achieved by amendment of a website than by adaptation of the product’s manufacture.

Is patent marking always appropriate?

Patent marking a product gives an “early warning” to others of the existence of patent rights, which may be vital for the award of full damages in patent infringement proceedings.  Furthermore, marking is generally straightforward and inexpensive.  It is therefore recommended for the majority of patented products.

However, not all goods lend themselves readily to patent marking.  Take wristwatches, for example.  A typical watchcase carries a variety of markings, in particular relating to the manufacturer and the technical specification of the watch.  The information presented may include the watch movement, calibre, serial number, lens crystal type, level of water-resistance, hallmarks, and so on.  Buyers generally expect to see these markings because they serve to confirm the origin of the watch and the standard of its manufacture.

In luxury timepieces, the markings are carefully arranged and beautifully engraved on the case in order to enhance visual appeal.  With limited space available, the addition of prominent patent markings risks overcrowding the watchcase and spoiling the aesthetics.  Moreover, discerning buyers may object to the inclusion of the patent information, however discreetly presented, because it has no relevance to the specification of the watch itself and is therefore unimportant to them.  Thus patent markings may be a detriment to the watch in the buyers’ eyes.

It is therefore understandable that makers of luxury watches might prefer to omit patent markings from their products, in spite of the risk of lesser protection from infringement.

The same might apply to other goods where visual appeal is a top priority for customers.  An example is handcrafted shotguns, which traditionally feature highly elaborate metal engraving.  Gunmakers may decide against applying patent markings, out of concern that they might detract from the superb workmanship on display on their products.

If these concerns for aesthetics prevent rights holders from directly and permanently marking their patented products, they might instead try to protect themselves by marking the products indirectly.  For example, a removable sticker or tag may be applied to the product, or the product packaging may carry the patent markings.

Indirect patent marking is a less preferable option, since it is unclear in UK law whether it will provide sufficient notice of the existence of patent rights.  It is therefore not certain whether indirect marking will confer the same benefits as a direct application of a patent mark to a product.  On the other hand, in some cases indirect marking may be the only viable option, and is probably better than having no patent marking at all.


This short article has explained that the primary purpose of patent marking is to give the patent owner the best chance of receiving damages for patent infringement.  The practical implementation of patent marking has been described, including “virtual marking”.  The article has highlighted that patent marking of products is generally recommended, but in some exceptional cases marking might be precluded by other commercial considerations.

If you want to find out more about patent marking your products, please contact Stuart via Stuart.Arnott@gje.com