PCT Receiving Office Guidelines

Chapter VII: Priority Claims and Priority Documents

Requirements for Priority Claims

166. If the request contains (Box No. VI of the request form) a priority claim, the receiving Office checks whether the priority claim is valid, as outlined below.

(a) The earlier application must have been filed either in or for a country which is party to the Paris Convention for the Protection of Industrial Property ("Paris Convention"), or in or for any Member of the World Trade Organization that is not party to the Paris Convention (Article 8(1) and Rule 4.10).

(b) The priority claim must contain the following indications (Rule 4.10):

(i) if the earlier application is a national application:

- the date on which the earlier application was filed;

- the number of the earlier application;

- the country in which the earlier application was filed;

(ii) if the earlier application is a regional application:

- the date on which the earlier application was filed;

- the number of the earlier application;

- the authority entrusted with the granting of regional patents under the applicable regional patent treaty (in practice, the regional Office concerned); and,

- where at least one of the countries party to the regional Treaty concerned is neither party to the Paris Convention nor a Member of the World Trade Organization, at least one country party to the Paris Convention or a Member of the World Trade Organization for which the earlier application was filed (Rule 4.10(b)(ii));

(iii) if the earlier application is an international application:

- the international filing date;

- the international application number;

- the receiving Office with which it was filed (in practice, this is indicated by the two-letter code which is part of the international application number).

(c) In addition, where the earlier application is a regional application or an international application, the applicant may, if desired, indicate one or more countries party to the Paris Convention for which that earlier application was filed (Rule 4.10(b)(i)), even if it is not required by Rule 4.10(b)(ii) (see item (b)(ii), above). Such optional indication must be made in the Supplemental Box.

(d) PCT Article 8(2)(a) and Article 4C(1) of the Paris Convention require that the date on which the earlier application was filed must be a date falling within the period of 12 months preceding the international filing date. Rule 2.4(a) defines the "priority period" accordingly. It should be noted, however, that Rule 26bis.2(c)(iii) provides that a priority claim shall not be considered void if the international filing date is within two months from the date on which the priority period expired. It should be further noted that Article 4C(3) of the Paris Convention provides that if the last day of the priority period is an official holiday or a day when the Office is not open for the filing of applications, the period shall be extended until the next working day of the Office. Rule 80.5, implementing extensions of time periods which expire while the relevant Office is closed or no mail is delivered, applies mutatis mutandis to the priority period (Rule 2.4(b)) and directly to the two-month period from its expiry.