Can I disclose my invention after an initial patent application has been filed?

Can I disclose my invention after an initial patent application has been filed?

This is a thorny issue. Patent applicants are often under pressure to make non-confidential disclosures of their inventions once a first patent application has been filed. This might be in order to publicise or sell their inventions, or because potential licensees and commercialisation partners are not prepared to sign confidentiality agreements, or because there is a desire to publish an academic paper. However, as the example below illustrates, making a non-confidential disclosure of an invention, even after filing an initial patent application, can seriously or fatally compromise the scope of protection that can validly be obtained.

This arises because the patent application procedure deliberately provides a mechanism for additional information to be included in a patent family within the first year of the patent application procedure. You can never add subject matter to a patent application, but you can file a supplementary patent application with new information, or add new information when filing internationally with a priority claim, in the first year of the patent application procedure, and so end up progressing patent applications which contain both the information included in an initial patent application and information added in the first year. However, any information which was not included in the initial patent application will not be entitled to the priority date of the initial patent application and so will require to be patentable over intervening disclosures. As the following example shows, this can be more of a concern in practice than one might expect.

As well as patentability concerns, another reason to delay disclosures is that many high-technology inventions which are the subject of pending patent applications are commercialised using confidentiality agreements, maintaining secrecy for as long as possible. Indeed, in the UK, confidential information can be protected by the law of confidence as well as by contract law, where there is a contract. Once information is made public, it is not confidential and cannot in principle be protected with a confidentiality agreement and so this commercialisation option is weakened or lost.

Where our clients are under pressure to disclose their inventions, we help them to understand in detail the risks involved in making non-confidential disclosures and discuss what types of disclosure minimise risks. We review whether their patent application(s) already on file are likely to be adequate, or whether they may need to file further patent applications before disclosures are made. We aim to enable our clients to make an informed decision as to what to disclose, to whom, how and when.

The following example serves to illustrate the problem posed by non-confidential disclosures made after the filing of a first patent application.


Imagine that an inventor is the first person to devise the idea of a bicycle that has a bell. They file a patent application that describes the idea. A week later, the inventor issues a press release describing the bicycle with a bell and demonstrates it in public, putting the idea firmly into the public domain. The patent application already on file is not in itself affected by these disclosures. The inventor may think the disclosure is therefore irrelevant.

A week later, the inventor realises that the idea could have broader application and that a bell could usefully be fitted to a train, a car, a truck or any other type of vehicle. The inventor wishes to obtain patent protection with broader scope and files a revised patent application, including the broader concept of a vehicle with a bell.

If the inventor had not disclosed his invention, the revised patent application might have led to the grant of a valid patent for the broader idea of a vehicle with a bell. Unfortunately, as a result of the disclosures, the idea of a vehicle with a bell is not now new. This is because one example of a vehicle with a bell (namely the bicycle with a bell) is already known to the public due to the press release and demonstration. Thus, a broad claim to a vehicle with a bell is now invalid due to a lack of novelty, at least in Europe. (Claiming priority from the first application does not help as the earlier application only disclosed a bicycle with a bell and so this priority claim would not be valid under current European Patent Office practice).

Specific claims to, for example, a train with a bell, or a car with a bell, may be new, but it would be very difficult to argue that any of these concepts are inventive over public disclosure of a bicycle with a bell.

In this example, disclosure has prevented the inventor from broadening the scope of his protection, at least by way of a UK or European Patent. Disclosures after the filing of a first patent application can also cause serious or fatal problems in other circumstances, for example, where:

  1. the patent applicant subsequently wants to narrow the scope of protection sought to include specific features which were not fully disclosed in the initial patent application;
  2. the patent applicant subsequently wants to otherwise amend the scope of protection sought in a way that was not disclosed in the initial patent application, perhaps as a result of becoming aware of previously unknown prior art when they receive an official search report during the priority year; or
  3. it is discovered that the initial patent application is invalid or cannot be used as the basis for a valid priority claim, perhaps because the example given in the initial patent application turns out not to enable the skilled reader to carry out the invention.

Possible Misunderstandings

Those who are new to the patent application process might mistakenly think that having filed an initial patent application gives a priority date in some general sense which applies to "their invention" rather than understanding that the protection potentially arising from an initial patent application is based on precisely what is disclosed in their initial patent application.

Those who are fairly familiar with the patent application process will not be surprised that if a whole new invention is made after an initial patent application has been filed, that initial patent application will not protect it, and any intervening disclosure of the new invention before a further patent application is filed would be fatal in the UK and Europe. However, they may not have thought through the scenarios above in which it can be beneficial to include new information or claims in a patent application within the priority year without any fundamentally different invention having been made and how this option can be lost by making an intervening disclosure.


In order to avoid compromising the scope of patent protection that can be obtained, the best legal advice is to not make non-confidential disclosures of an invention even once an initial patent application has been filed. This is especially true if technical development of the idea is ongoing. If commercial realities mean that it is desirable to make non-confidential disclosures, then it is important to check that patent filings are up to date and to take legal advice beforehand in order to understand and, if possible, minimise the risks involved.

Further information about disclosing inventions is summarised in this PDF.

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