Patent Prosecution Highway

To offer applicants a faster route to patent allowance, reduce patent office workloads and streamline procedure, many patent offices have looked into ways of ‘sharing’ their work. The Patent Prosecution Highway consists of a network of agreements between various patent offices allowing applicants to accelerate prosecution in one office using positive examination results received from another office. This page provides a general overview of the PPH system and its requirements.

What is PPH?

The Patent Prosecution Highway offers a mechanism by which positive examination results in one office can be submitted to a second office to accelerate patent prosecution in the second office. That is, prosecution of a second application can be accelerated on the basis of positive results in examination of another application(s). There are two ‘types’ of PPH.

  1. PPH based on domestic work products. This is the most prevalent. Here, the first office is a first domestic office, and the second office is a second (different) domestic office.
  2. PPH based on PCT work products. Here, the first office is the International Search Authority (ISA) (it must also be the International Preliminary Examination Authority (IPEA) if a demand was filed), and the second office is a domestic office.

Why would I want to use PPH?

If a positive examination result has been obtained in one location, and the same scope of protection is wanted in other geographic territories, PPH can make it much easier for you to get quick grant of corresponding pending patents in those territories.

What is needed to qualify for PPH?

A separate PPH agreement exists between each pair of offices, in each single direction. [For example, between the USPTO and the EPO there are four agreements: PPH at the USTPO based on domestic EPO examination, PPH at the USPTO based on international EPO examination, PPH at the EPO based on domestic USPTO examination, and PPH at the EPO based on international USPTO examination.]

The core requirements are broadly common to each agreement, although there are exceptions. There are some intricacies for certain of the offices and certain of the agreements. A few of the most important are set out below.

The core requirements are generally:

(1) The second application (at the second office) must have a "corresponding" first application(s) (at the first office). What constitutes a "corresponding" application varies from agreement to agreement. Generally, the second application must be linked to the first application(s) either by priority, by PCT origin, or by common ultimate parent.

(2) At least one claim in each first application must have been indicated as being allowable by the first office. Where the first office is an ISA or IPEA, allowability in terms of novelty, inventive step and industrial applicability is all that is required. A copy of the allowable claim(s) must be submitted.

(3) Each of the second application’s claims must ‘sufficiently correspond’ to one of the claims indicated by the first office as being allowable in the first application(s). (Some flexibility is allowed to, for example, present claims which are more limited than those indicated as being allowable.) A claim correspondence table may be used to show this.

(4) Examination by the second office must not have begun.

(5) Participation in the PPH program must be requested. Most offices provide a form to submit for this.

(6) Copies of each official action (of relevance to patentability) issued by the first office must be submitted to the second office.

(7) Copies of each non-patent document cited in the prosecution by the first office must be submitted to the second office.

Intricacies of some agreements include:

(a) Translations of the allowable claims and official actions are sometimes required (depending on the first office and second office).

(b) Translations of cited documents (be they patent or non-patent) may be requested by the second office.

(c) At the USPTO, applicants must also submit copies of all non-US patent citations.

(d) At the USPTO, applicants must also submit official actions relevant to patentability which issue after the one indicating allowability.

(e) At the USPTO, continuation applications do not ‘inherit’ the PPH status of their parent.

(f) Where the PPH request is based on the WOISA or IPER, the applicant can submit amendments or arguments in an attempt to overcome any objections noted in Box VIII ("certain observations on the international application" - typographical errors, clarity and so on).

(g) Offices may charge a fee for using the PPH scheme.

It is advisable to check the requirements set out in a particular agreement before making use of PPH under that agreement, since exceptions to many of the "requirements" exist.

Several offices give the applicant a single opportunity to correct deficiencies in their PPH request. Those offices also note that examination will not be suspended or put off to allow time for the PPH request to be corrected. If examination begins, the PPH request is (generally) not allowable (see requirement (4) above).

PPH can be applied for as many times as is wanted, as long as the above requirements are met. So, refusal of a PPH request is not necessarily the end.

What do you get out of doing PPH? What don’t you get?

The specific benefit of PPH participation varies from country to country. Generally, some form of accelerated examination is given. This may be within a pre-existing acceleration framework (e.g. the PACE framework in the EPO - for more information, see our sheet entitled "Accelerated Prosecution") or using a less defined ‘acceleration’ (e.g. "advancement out of turn for examination" in the USPTO). The EPO give acceleration throughout the examination process (as long as the PACE requirements are met). The PACE acceleration framework is available to all applications - PPH is not essential.

PPH does not offer a guarantee of allowance. Nor does it allow for complicated claim strategies (e.g. where different prior art documents are available in different countries).

PPH is not a ‘filing’ initiative. The first and second applications at the first office and second office must already be existence for a PPH application to be made. It does not offer any ability to, for example, file new applications outside the priority year, or ‘convert’ a granted European patent into a US patent.

Who does PPH?

An ever growing number of PPH agreements exists. If you are interested in a specific combination of first office and second office please get in touch with your usual Mewburn Ellis contact.

The UKIPO and EPO both have a large number of agreements with patent offices around the world, including the USA, Japan, Korea, China, Canada and Australia.

More information

The PPH program is coordinated by the Japanese Patent Office. A large amount of information can be found on their website at

A useful table of all PPH agreements can be found at

This information is simplified and must not be taken as a definitive statement of the law or practice.