Divisional Patent Applications

Patent applications are typically written with one invention in mind, and a granted patent must relate to one invention – this is to meet the requirement of “unity of invention”.

That said there can be advantages to including subject matter relating to multiple inventions in a single application. For example, this can give you flexibility to amend the application to your preferred invention at a later stage, without having to incur costs associated with filing multiple applications.

However, let’s assume that you file your single application including multiple inventions and you decide that you would like to have protection in place for all inventions? Is this possible?

Fortunately, yes!

It is not possible to cover all unrelated invention using the single initial application, but it is possible to file one or more “divisional applications”, which branch off from the initial “parent application”. Each divisional application can relate to a unique invention as long as the subject matter was initially included in the parent application.

A divisional application must be filed prior to grant of the parent application (or any preceding divisional application). Each divisional application will be subject to its own examination process and in this way a single patent application can lead to multiple granted patent rights.

A divisional application can also be beneficial in cases where the claims of a patent application have been amended during the examination stage in a way that excludes potentially patentable subject matter.

Strategic Considerations

The same level of care should be applied in determining whether to file a divisional application as you devoted to your initial application – just because you can file a divisional application does not necessarily mean that you should.

There may be a diminishing returns effect where each subsequent divisional application covers smaller aspects of your activities. Of course, a small aspect of your activities not covered by the parent patent may be critical to a competitor’s activities, and therefore worthy of additional investment.

A patent attorney will have these ideas at the back of their mind when advising on filing strategy and the grant process.


At Scintilla, we help innovative companies get a grip on their intellectual property. Our unique commercial approach combines registration of patents and trade marks with strategic input so that IP can be a springboard for business growth. If you would like to discuss your IP needs, do contact us or book a free initial consultation!