Since July 2, 2012, third parties can submit prior art observations during the International Phase of an application under the Patent Cooperation Treaty (PCT). These observations refer to prior art which the third party believes to be relevant to the patentability of the International Application solely for reasons of novelty and/or inventive step. Third party observations can be submitted at any time starting from the date of publication of the International Application until its 28-month expiration from the priority date. They must be filed at the International Bureau (IB). No official fee is associated with this service at this time.

Each observation may contain up to ten (10) prior art references. Each observation should point to specific passages of the identified prior art and contain a brief description of their relevance. The filing can only be done electronically through ePCT or PATENTSCOPE, and submissions may be made anonymously, if desired.

Before making an observation available to the public via PATENTSCOPE and to the International Authorities which have not issued their report yet, each observation is first reviewed by the IB to ensure that the observation indeed relates to questions of novelty and/or inventive step. The Applicant has until 30 months after the priority date to respond to the observation should he/she choose to do so, in which case the response will also be made public.

The IB will thereafter transmit any third party observation and also any response made by the Applicant to the designated Offices of the countries where the Applicant desires patent protection. Some Offices have set up automatic transmittal of such information, while others request it specifically. However, there is no guarantee that the individual Offices will consider the observations during the Examination process of a patent application under National Phase.

A third party observation can be an interesting tool to use when one closely monitors competitors. In some cases, relevant prior art of which one is aware may not have been indicated in the published International Search Report of a PCT Application filed by a competitor. One may want to draw this information to the attention of the National Offices responsible for the Examination of patent applications before the patent is granted and more specifically, as early as possible in the life of the application. In cases where an observation is submitted before the issuance of the International Search Report, the prior art discussed in the observation may be taken into account in the report. By filing an observation during the International Phase, one may save costs, as only one submission is transmitted to each designated Office concerned.

Finally, a careful review of all relevant prior art is advised before filing an observation during the International Phase, since any third party can only file one observation per International Application, and once submitted, the third party cannot modify or retract it. Early filing is also preferred since a maximum of ten (10) observations can be filed per International Application.