In respect of obtaining patent protection in a number of territories around the world, this is often achieved by submitting a patent application in an initial first territory (usually where the applicant is based), and then following this up with a second international PCT patent application to initiate the process for pursuing patent protection in the remaining territories where patent protection is ultimately required.

The deadline for validly submitting this second PCT patent application in general terms is 12 months from the date when the first patent application was applied for. If this 12 month priority deadline is missed, it is possible under certain circumstances to extend this deadline by up to an additional two months. However, for this extension to be permitted, it is necessary to undergo a process of restoration, which involves providing a valid explanation as to why the original 12 month deadline was missed. Depending on the territories where patent protection is then ultimately pursued from the PCT patent application, this explanation requires demonstrating that missing the original 12 month deadline was either unintentional (the so called "unintentional" test, which is employed at least by the UKIPO in respect of UK patents), or requires demonstrating that the deadline was missed in spite of all due care having been demonstrated under the circumstances (the so called "all due care" test, which is invariably more strict than the "unintentional" test, and which is employed at least by the EPO in respect of European patents).

Whether it is possible to fulfil either these unintentional or all due care tests will inherently depend on the chain of events which led to the original 12 month priority deadline being missed. Certainly however, there is never a guarantee that a restoration request will be allowed. Where the restoration request is refused, this could prove fatal to the PCT patent application in cases where a relevant disclosure of its invention occurred between the filing date of the first priority patent application and the subsequent PCT patent application.

Mindful of the above, it is to be noted that in situations where the 12 month deadline has only just been missed, for example, by a day or two, it may nonetheless be possible to validly extend the 12 month deadline without the need for a restoration request. This process relies on two aspects of the PCT system, namely:

  1. the fact that a PCT patent application can be applied for at a number of different receiving offices around the world; and
  2. where a receiving office is closed on a given day, any deadline for submitting a PCT patent application before that receiving office on that day will roll over to the next working day when the receiving office is open.

Accordingly, where the 12 month priority deadline falls on a day when a given receiving office is closed, for that receiving office only (but not for any other receiving offices which are open on that day) the priority deadline will then be extended/rolled-over until the next working day when the receiving office is open. Accordingly, if the 12 month priority deadline has only just been missed, it is worth checking whether any receiving office(s) around the world was closed on the day when the 12 month deadline expired, to see whether it is still possible to submit the PCT patent application before that receiving office on the next day when it is open. If so, it may still be possible to submit the PCT patent application before that receiving office in a way which allows the priority claim for the PCT patent application to be considered valid, and in a way that does not require restoration.

Inherently, if the above route of submitting the PCT patent application before a previously closed receiving office is to be adopted, action must be taken swiftly after the initial 12 month priority period passes. However, in situations where this "backdoor" route is available for timely submitting the PCT patent application before a previously closed receiving office, it may provide an effective resolution for retaining an otherwise lost priority claim back to the original first patent application, and in a way that obviates the need to undergo the onerous restoration process.