UK IPO Patent Decision - Divisional patent applications

A recent decision (O/0308/25) by the UK IPO highlights how different acts are treated when the UK IPO is closed for business and the potential for serious adverse consequences when mistakes are made. 

The Applicant filed two divisional patent applications on 30 November 2024. As the divisionals would be filed less than 3 months before the end of the compliance period on 30 December 2024, they also filed a request to extend the compliance period by two months.

Normally this would not be a problem. The compliance period would be extended to 28 February 2025 and the divisional patent applications would thus have been filed within three months of the end of the compliance period. However, the 30 November 2024 was a Saturday and the UK IPO is closed on weekends. Most actions performed over the weekend are treated by the UK IPO as having occurred on the next working day. However, this does not apply to the filing of divisional applications.

This meant that the UK IPO treated the two divisional applications as being filed on Saturday 30 November 2024, but the request to extend the compliance period was treated as being filed on Monday 2 December 2024. The consequence of this was that the compliance period was not extended at the time of filing the divisional applications. The divisional applications were treated as late filed and lost their status as divisionals.

The Applicant requested that the UK IPO apply discretion to allow the late filing of the divisional patent applications. The UK IPO was not convinced that discretion should be applied due to the lack of exceptional circumstances being identified at the time of filing the divisional applications, and the fact that Applicant waited until the last possible moment to file the divisional applications despite having the opportunity to do so at an earlier date.

In this case, the Applicant delaying actions until the last possible moment and misunderstanding how different actions are treated when the UK IPO is closed for business had serious consequences for their patent applications. The decision highlights that Applications should:

• exercise care when deadlines fall on a day when the UK IPO is closed for business;

• avoid filing divisional applications at the last possible moment; and

• if they have filed something late, identify the exceptional circumstances to the UK IPO at the time of filing.

Explainers:

Divisional patent applications 

A divisional patent application is essentially a “child” application that is split off from an existing “parent” application. While the divisional application is filed later than the parent application, it is treated as having been filed on the same date as the parent application.

Reasons for filing a divisional application include:

• to pursue claims that you had to delete from the parent application in response to a unity objection

• to obtain claims for subject matter disclosed, but never claimed, in the parent application

• for strategic reasons particularly when the application is commercially important.

Before the UK IPO, divisional applications must be filed while the parent application is still pending (not granted, withdrawn or deemed withdrawn), and also must be filed at least 3 months before the expiry of the compliance period on the parent application.

Compliance period

The compliance period refers to the time frame within which a UK Patent application must be in condition for grant. 

The compliance period is either:

- four years and six months from the filing date or priority date, if earlier; or

- 12 months from the issuance of the first substantive examination report if that gives a later date than the standard four years and six months.

A two-month extension to the compliance period is available as of right. Further extension may be granted at the discretion of the UK IPO.