First published in Intellectual Property Today


The five largest patent offices are the U.S. Patent and Trademark Office (USPTO), the Japanese Patent Office (JPO), the Korean Patent Office (KIPO), the Chinese patent office (SIPO) and the European Patent Office (EPO). These five offices (the "IP5"1) handle over 90% of the worldwide patent workload, and have undertaken a program of cooperation which aims to reduce duplication of their work, enhance patent examination efficiency and quality, and guarantee stability of the patent rights they grant.

The Patent Prosecution Highway (PPH) program is based on the premise that claims found allowable by one patent office should form the basis for accelerating examination of "sufficiently corresponding" claims in a second patent office. The patent office in the second jurisdiction takes advantage of the work of the first, saving both the second patent office and applicant time and cost of duplicate efforts. There have been various PPH initiatives over the years involving the IP5 and other patent offices. The IP5 pilot program was set up with the aim of further harmonizing and improving the PPH process among these five patent offices.

In practice, however, some patent offices treat PPH applications very differently to others. We describe below some practical considerations and steps to take advantage of the benefits of the PPH, while steering clear of the potholes.  

PPH in the United States

The USPTO was an early adopter of the PPH and is its largest user, both in terms of PPH applications filed, and allowed claims used as the basis for PPH applications in other patent offices.

For applicants with claims granted outside the United States, the PPH program appears attractive because, compared to the average application, PPH applications enjoy significantly increased allowance rates (86% vs. 53%) and decreased pendency times (11 vs. 31 months).2 However, because PPH applications have already been through an entire prosecution cycle in another patent office, they usually arrive at the USPTO with their claims already significantly narrowed compared with a typical unexamined application, which goes some way to explain the increased allowance rates. And even though a PPH application is placed on the examiner's "special" docket, examination times depend heavily on the number of other matters on the examiner's special docket. Thus, the faster prosecution times under the PPH are likely due to prosecution beginning earlier.

One clear advantage of filing a PPH application with the USPTO is cost. There are no filing fees associated with applying to the PPH program (unlike some of the other ways in which applications can be "made special"), and attorney time required to prepare and submit the required forms and amend the claims to their as-allowed form is often relatively modest.

The benefits of improved grant rates and pendency under PPH have to be balanced with the potential downside that an applicant may leave valuable subject matter unclaimed. Prosecution in the first examining country may have unnecessarily narrowed claim scope in order to gain their allowance.

A more costly alternative to the USPTO PPH is to file a Track 1 or accelerated examination. (Track 1 is $4,000 for large entity, $2,000 for small entity, and $1,000 for micro-entity). This expedited prosecution could lead to the broadest possible claims in the shortest time. These hard-fought claims could then in turn be filed in other patent offices using reciprocal PPH programs subject to the pros and cons described below. Granted U.S. claims are often given considerable deference, and several patent offices automatically allow claims corresponding to granted U.S. claims.

Another alternative is to file an additional continuation application with broader claims than those allowed in the first examining office and used as the basis for the PPH application. This option incurs the additional costs associated with a separate filing, but allows the applicant greater freedom in crafting claims more suitable to the U.S. jurisdiction rather than limiting the claims to the one-size fits all approach of the PPH.  

PPH in the European Patent Office

The PPH program operates very differently at the EPO. Anecdotal evidence suggests that PPH applications at the EPO actually have lower rates of allowance and longer pendencies than the average. This reverse outcome is possibly due to the EPO insisting that its own substantive search and examination procedures are applied to PPH applications, irrespective of the application's prosecution and granting in another country. The EPO currently provides no data on PPH applications other than the number of applications filed and there is no data available to suggest that PPH at the EPO provides any recognizable improvement in speed or outcome.

As an alternative to using the PPH at the EPO, applicants can file for accelerated examination using the PACE program. No additional fees or modification of claims are required and the request can be made at any time while the application is pending. Acceptance is discretionary and when "practically feasible and subject to the workload of search and examining divisions." PACE generally works well, but the program is highly dependent on an examiner's workload and backlogs in specific art groups reduce the program's effectiveness.

An advantage of an early grant of European claims is that the USPTO readily accepts them. Again, anecdotal evidence suggests high allowance rates and short pendency for PPH applications filed at the USPTO with claims already granted by the EPO.  

PPH in Korea

On the basis of available data, the KIPO appears very PPH-friendly. PPH applications in Korea enjoy significantly higher allowance rates (89% vs. 66%) and dramatically shorter pendencies (5 vs. 21 months) than the average. However one limitation of using the PPH in Korea is the need to preemptively preserve rights to subject matter beyond that claimed in the PPH application. Because the KIPO may issue a notice of allowance without issuing an office action, and a divisional application may only be filed in response to an office action or before a notice of allowance, it is prudent to file a divisional application along with the KIPO PPH application.  

PPH in Japan

Along with the USPTO, the JPO was an early adopter of PPH and is the second in terms of PPH applications filed and allowed claims used to support PPH applications in other patent offices. In Japan the allowance rate for PPH applications is slightly higher (75% vs. 69%), but processing time is much faster (7 vs. 25 months) than the average. However some practioners caution the use of PPH in Japan as they have experienced significant delays compared with traditional prosecution. For example, some PPH applications have received a significant number of office actions even though the claims were previously granted in another patent office. It appears that the JPO, at least in some instances, may not rely on the search results and examinations of other patent offices in processing PPH applications.  

PPH in China

China's PPH program is relatively recent and reliable statistics were not available to the authors. Initial reports suggest that SIPO is taking a cautionary approach to the PPH, but initial comments have generally been favorable. Given the short period of time for which PPH has been available, a significant number of PPH applications have been made, notably based on USPTO or JPO allowances.  

PPH in Other Countries

Canada and Taiwan show similar high allowance rates and significantly improved pendencies as those in the United States. Great Britain, Australia, and Russia have todate granted 100% of the PPH applications they received. Pendency from the PPH request to final decision is lightning fast in Mexico (0.8 months) and Australia (1.7 months), and very fast in Russia, Taiwan, Great Britain, and Canada (ranging from 4 to 6.2 months). These statistics strongly support filing PPH applications in these jurisdictions.

In view of the lack of obvious favorable treatment of PPH applications by the EPO, applicants may consider filing their PPH applications nationally at the patent offices of individual European countries. Some 80% of EPO filings are validated in only the UK, Germany, and France, and about 90% are validated in those three countries plus Italy and Spain. Neither France nor Italy subject patent applications to substantive examination. The remaining three countries are all members of the PPH program, so direct filings with PPH applications in multiple countries may provide a faster and more cost effective way to get useful protection than going via the EPO.

Pursuing claims in the UKIPO may be particularly attractive to applicants wishing to obtain protection in the United States as the process is relatively inexpensive, fast (offering accelerated examination for applicants wishing to use the PPH), and the granted claims are generally viewed favorably by the USPTO.  


Driving a patent application along the PPH can be fast and relatively inexpensive experience. But as with real life highways, the PPH has some large potholes for the unwary. The increasing use of PPH will likely add to the congestion, but with careful planning it can make for a pleasant ride. Consider the criticality of your patent application, where you need patent protection, the scope of subject matter you need to protect, how that scope may vary across different countries, the timing for obtaining protection, and cost limitations. These factors will dictate your choice of using the PPH or sticking to the road of traditional prosecution.