Is 12-month Paris Convention priority claim deadline extendable?

Question

This question asks if a priority claim under the Paris Convention can be made after the 12-month deadline, and the accepted answer is 'no'. However, I wanted to ask again if this is really the case. Specifically:

(i) Does the Paris Convention or PCT allow for an extension (e.g. due to 'unintentional' error)?

(ii) Do individual countries allow for an extension?

---

It appears that the PCT in fact mandates ('shall') a 2-month extension for unintentional delay.

PCT 26 bis.3(a)

Where the international application has an international filing date which is later than the date on which the priority period expired but within the period of two months from that date, the receiving Office shall, on the request of the applicant, and subject to paragraphs (b) to (g) of this Rule, restore the right of priority if the Office finds that a criterion applied by it (“criterion for restoration”) is satisfied, namely, that the failure to file the international application within the priority period: (i) occurred in spite of due care required by the circumstances having been taken; or (ii) was unintentional.

See MPEP 213 for the US implementation.

35 USC 119

The Director may prescribe regulations, including the requirement for payment of the fee specified in section 41(a)(7) , pursuant to which the 12-month period set forth in this subsection may be extended by an additional 2 months if the delay in filing the application in this country within the 12-month period was unintentional.

37 CFR 1.55(c)

Delayed filing of subsequent application. If the subsequent application has a filing date which is after the expiration of the period set forth in paragraph (b)(1) of this section, but within two months from the expiration of the period set forth in paragraph (b)(1) of this section, the right of priority in the subsequent application may be restored under PCT Rule 26bis.3 for an international application, or upon petition pursuant to this paragraph, if the delay in filing the subsequent application within the period set forth in paragraph (b)(1) of this section was unintentional. ...

Answer 1

In a nutshell, NO, the 12 month priority period is non-extendable. BUT... in legal stuff there is almost always an available remedy for time limits. This is only for rare and extreme cases though.

What if you are ready to file your application on the last day of the priority period and suddenlty your computer breaks down and you don't have copies of your files anywhere else? You would need at least a few days to recover your files and file the application and by then the 12M period will have lapsed.

Under the PCT, you can request restoration of priority right according to Rule 26bis.3 of PCT (Restoration of Right of Priority by Receiving Office). See also PCT-Applicant's Guide point 5.063 and onwards. You have "two months from the date on which the priority period expired" to do that. BUT, you need to prove either that "the failure to file the international application within the priority period occurred in spite of due care required by the circumstances having been taken"

OR that

"the failure to file the international application within the priority period was unintentional".

The offices require serious evidence and they won't accept excuses, there has to be a major difficulty which prevented you to comply with the 12M period.

Mind that some Receiving Offices might have declared "reservation" with respect to this rule. It might also be the case that while the Receiving Office (of a PCT procedure) accepts your arguments, another national patent office (in national phase entries) will not.

The USPTO does accept requests for restoration of priority rights as receiving office within the PCT procedure, so it makes sense that they have a similar provision for US proceedings as well.

Answer 2

It appears that a 2-month grace period was added as part of the PLTIA (effective Dec 18, 2013). See this article:

The rule changes also permit the restoration of a priority claim in a U.S. application that is filed more than 12 months after the priority application (which can be a foreign or provisional application). Prior to this change, it was not possible to claim priority to foreign and provisional applications filed more than 12 months earlier. Priority can [now] be restored in pending applications filed no more than 2 months after the 12-month statutory filing period. For design patent applications, the subsequent application must be filed no more than 2 months after the 6-month statutory filing period. ...

---

Also, note the distinction between filing the app that claims priority, and actually claiming priority. The discussion in the question relates to the former matter, but the latter matter may have distinct deadlines. E.g., see the US requirements in MPEP 211.03:

If the application is a utility or plant application ..., the benefit claim of the prior application ... must be made during the pendency of the application and within the later of four months from the actual filing date of the later-filed application or sixteen months from the filing date of the prior-filed application. If the application is a nonprovisional application entering the national stage from an international application under 35 U.S.C. 371, the benefit claim must be made within the later of: (1) four months from the date on which the national stage commenced ...; (2) four months from the date of the initial submission under 35 U.S.C. 371 to enter the national stage; or (3) sixteen months from the filing date of the prior application. This time period is not extendable ... unless a petition to accept an unintentionally delayed benefit claim is granted. ...