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PCT Newsletter 09/2011: Practical Advice

WARNING: Although the information which follows was correct at the time of original publication in the PCT Newsletter, some information may no longer be applicable; for example, amendments may have been made to the PCT Regulations and Administrative Instructions, as well as to PCT Forms, since the PCT Newsletter concerned was published; changes to certain fees and references to certain publications may no longer be valid. Wherever there is a reference to a PCT Rule, please check carefully whether the Rule in force at the date of publication of the advice has since been amended.

The consequences of filing the international application between 12 and 14 months from the priority date

Q: I am going to file an international application claiming the priority of an earlier national application. The priority year will expire in two days and, for operational reasons within my company, it will be very difficult to have the international application ready before then. However, I understand that in any case, if the international application is filed within two months from the date on which the priority expired, the priority claim will be maintained. Is this the case?

A: In order to validly claim priority of an earlier application, an international application must always be filed within the priority period, which is 12 months from the filing date of the earlier application whose priority is filed (see PCT Rule 2.4); otherwise, the right of priority will be lost. You may have confused the fact that, where the international application is filed within two months from the date on which the 12-month priority period expired, the priority claim will not be considered void for the purposes of the international phase, and all time limits during the international phase will still be calculated from the earliest priority date, even where no action is taken to restore the right of priority (see PCT Rule 26bis.2(c)(iii)).

If you do not file the international application before the expiration of 12 months from the priority date, but do so within two months from the expiration of that time limit, you may be in a position to request restoration of the right of priority. Requesting restoration of the right of priority is a fairly complex procedure, and several requirements must be met. Those requirements were discussed in detail in earlier “Practical Advices” (see references at the end of this “Practical Advice”), but the following information outlines briefly the points that you should be aware of if you ultimately wish the right of priority to be restored in the national phase.

The request for restoration must be filed with, and in some cases, a fee must be paid to, the receiving Office within the time limit of two months from the expiration of the priority period, and must be supplemented by a statement explaining the reasons for the failure to file the international application within the priority period; in some cases, a declaration or other evidence in support of the statement of reasons should also be submitted (PCT Rule 26bis.3(f)).

As far as requests for restoration before the receiving Office are concerned, one of the following criteria for restoration must be satisfied, depending on the criteria applied by the receiving Office: the failure to file the international application within the priority period occurred in spite of due care required by the circumstances having being taken, or the failure to file the international application within the priority period was unintentional.

Even if the receiving Office restores the priority claim, the validity of that claim cannot be assured in the national phase, notably where the designated Office has notified the IB of the incompatibility of PCT Rule 49ter.1 with its national law, but it may also depend on whether the designated Office applies a more stringent criteria for restoration than the one applied by the receiving Office. Where the receiving Office has made a finding that the failure to file that international application within the priority period occurred in spite of “due care” having been taken, that restoration should, in principle, be effective in each designated State (PCT Rule 49ter.1), as this is the more stringent of the two criteria. However, where the receiving Office has restored a right of priority under PCT Rule 26bis.3 based on a finding that the failure to file that international application within the priority period was “unintentional”, the restoration will only be effective in designated States whose applicable national law provides for restoration based on that criterion, or on a criterion which is more favorable than that criterion (PCT Rule 49ter.1(b)). Note that not many Offices apply the less stringent “unintentional” criteria. You will need to consider whether the Offices before which you are considering entering the national phase will recognize a decision by the receiving Office on the restoration of the right of priority, and whether it would be easier to pursue the matter before the receiving Office, or upon national phase entry before the designated Office.

A number of patent Offices, in their capacities as receiving Offices and/or designated Offices, have notified the International Bureau (IB) that PCT Rule 26bis.3, PCT Rule 49ter.1 and/or PCT Rule 49ter.2 is/are incompatible with the national law applied by them, with the consequence that:

– some receiving Offices will not consider a request for restoration of the right of priority (hereinafter: “request for restoration”); and

– some designated Offices will not consider a request for restoration, and in certain situations, some may not accept a priority claim which has previously been restored by a receiving Office.

To find out which Offices have notified the IB of such reservations, see the table entitled “Restoration of the right of priority by receiving Offices (RO) and designated Offices (DO) under PCT Rules 26bis.3 and 49ter.2” at:


As far as receiving Offices are concerned, the IB in its capacity as receiving Office accepts requests for restoration and is competent for international applications filed by a national or resident of any PCT Contracting State.

It is important to note that if an applicant deliberately waits until the 12 month priority period expires to file an international application, he/she is unlikely to qualify for consideration under either the due care or the unintentional criterion.

Applicants are always strongly advised to file their international application well before the end of the 12 month priority period and should not rely on the fact that priority claims of international applications filed within two months of the 12 month priority period will not be considered void in the international phase. Even though it may be possible to restore the right of priority, it is much better to file your international application within the 12 month priority period, rather than engage in the relatively complicated procedure of requesting restoration. By filing before the end of the 12-month priority period, provided your application meets the minimum requirements under PCT Article 11, you should be able to address any defects in the application after filing without any consequential change in the international filing date.

Earlier “Practical Advices” give information on how and when to file a request for restoration (PCT Newsletter No. 04/2007), requesting the restoration of the right of priority where the receiving Offices does not apply such provisions (PCT Newsletter No. 09/2009) and choosing a receiving Office as a function of the criterion applied by it for restoring the right of priority (PCT Newsletter Nos. 10/2009 and 11/2009). Further information on requesting the restoration of the right of priority can also be found in the PCT Applicant’s Guide, International Phase, paragraphs 5.062 to 5.069, and the part of the “Frequently Asked Questions: Amendments to the PCT Regulations (April 1, 2007)” concerning the restoration of the right of priority at: