To Patent or To Prototype?

Many lone inventors ask this question during an initial consultation with us. What should they do first? File a patent application or develop a prototype? There is sometimes no definitive answer to the question as there can be arguments in favour of both.

However, there are two main factors to consider that will often provide the answer: ‘sufficiency’ and route to market. We will look at each of these in turn and then discuss other factors that should also be considered.


Finalized design drawings or a prototype are not necessary in order to file a patent application.

However, the invention must be sufficiently developed in order that it can be explained fully.

An application for valid patent protection can be filed if the patent attorney writing the application has enough information to describe at least one way of making the invention work such that a person reading the application can make the invention work without exercising any inventive effort.

If the invention is still in its infancy and there are inventive barriers to be overcome before the invention can be exploited then an application for valid patent protection cannot be filed.

Thus, in such circumstances more research and development is needed and most probably development of a working prototype.

Although a patent application for valid protection can’t be filed it may be helpful to do some patent searching so as to provide information that can assist with product development.

Route to Market

Many inventors have no real wish to start manufacturing and selling products that embody their invention. Instead a large proportion of inventors would prefer to license or sell any patent application or granted patent and simply receive payment from a company that wishes to exploit the invention.

In such instances it is essential to be able to obtain patent protection in order that there is something to license or sell.

Patent protection isn’t guaranteed. In order for something to be patentable the invention has to be ‘new’ in the sense that it hasn’t been done before, and it needs to be ‘inventive’ in the sense that it is not an obvious modification of the most similar things.

Thus, why spend money on product design or prototyping if protection is not going to be available?

We have met inventors who have spent thousands of pounds on designing a product, only to find that it is not protectable by a patent. As they had only ever wished to sell or license any patent they had wasted their money.

The best first step for such inventors is either a patentability search and/or the filing of a UK patent application with a request for combined search and examination.

Other Factors

Prior art. Every day that passes more and more information is published, all of which can be relevant to the patentability of an invention. In general terms the sooner a patent application is filed the better, as anything published after the application has been filed cannot be cited against the application so as to prevent grant of a patent.

Deadlines. Filing a UK patent application sets the clock ticking on the 12 month period for filing overseas patent applications and having them backdated to the date of filing the UK application. If sufficient funds for overseas applications will not be available within 12 months of filing then it may be preferable to delay the filing of the UK application and concentrate on getting the invention more fully developed. Any patent application could be filed just prior to launch of the commercial invention such that hopefully the invention pays for its own patenting.

Inventive concept. If it is clear that the inventive concept will not change through any prototyping or design process then filing a patent application is a possibility. However, if it is likely that the inventive concept may change or be augmented by prototyping then it is probably best to delay filing a patent application until the inventive concept is finalized. It should be noted that if developments are made after filing a patent application then it is often possible to protect them by filing one or more supplementary applications.

Infringement. If the exploitation of your invention will infringe any third party intellectual property rights then spending time and money on a prototype may be pointless. Thus, a ‘freedom to operate’ patent search at the outset might be preferable.


A separate but related consideration is that if you do engage a company to assist you in the prototyping process it is extremely important to establish at the outset a written agreement setting out who will own any IP rights developed during the prototyping process. The agreement should preferably include clauses stating that the company will assign all IP rights in developments to you and will execute any documents necessary for you to obtain grant of formal protection. We would recommend obtaining a professionally drafted agreement to ensure that you are in a strong position legally.

The circumstances of each inventor are unique and other factors may of course come into play. Various tactics are possible such as the withdrawal and re-filing of a patent application so as to delay the deadline for overseas applications or prevent publication.

However, whatever your circumstances we would recommend seeking professional advice on patenting your invention to help determine the best path for you.