Be a Patent Legal Status Search Expert!

I admit that the title of this post is a bit optimistic, given that I am far from a patent legal status expert myself, even after years of wading through the topic!  But I do have a secret weapon that often saves me from appearing totally clueless – the European Patent Office (EPO)’s Statistics, Coverage and Codes documentation pages.

In this post I’ll discuss a small fraction of the useful content available on the “Useful tables and statistics, codes and coverage” pages on These pages offer in-depth documentation of common patent bibliographic sources that are probably used by your commercial search provider. Read on to learn how these pages can save your bacon someday.

As our avid Intellogist readers know, the heart of just about every major patent database is a pair of database products, called DOCDB and the Inpadoc Legal Status file, respectively.  DOCDB contains bibliographic data from over 100 patenting authorities around the world, while the Inpadoc Legal Status file contains data from over 60 countries.   Both files are produced and maintained by the European Patent Office (EPO), which is no mean undertaking, and we should probably all be grateful that they own this endeavor and willingly license this data to anyone needing to build an international patent database.

Current coverage information is available at the EPO website under the “Updated weekly” documentation. The file “Contents and coverage of the INPADOC legal status file.xls” contains legal status coverage information broken down by country code, kind code etc. and includes known gaps and the date of last update.  It also indicates high-altitude information about whether the country coverage contains events such as reassignments, oppositions, invalidations, reinstatements, or term extensions  (not every country provides this important information).

Even a quick look through this document will be enough to show you that the file’s coverage is only as good as the data the national patent office provides, and that data is sometimes woefully incomplete. A good example is Italy, which apparently stopped sending updates in 2000.

Italian Legal Status Data in INPADOC

















PatentsandUtilityModels 2000/51




SPCs(medical) 2000/47




SPCs(herbicidal) 2000/47



EPOtranslations 2001/46



Feepayments 2000/11

Because of its ubiquity, it’s a good idea to understand the Inpadoc Legal Status file in detail.  The EPO works with the various national patent offices to normalize the data as much as possible by assigning codes to specific legal status events. But because of the procedural differences in each individual office, it’s difficult to fully normalize the data.  For example, some countries report changes in patent ownership (re-assignments) in their legal status data deliveries.  But unfortunately, each national office does it using its own terminology, which can vary greatly.  Below are some examples of assignment codes and their definitions, taken from “Legal Status Codes in English.txt” on the “Updated Weekly” section of the EPO’s website.

Inpadoc Assignment Code Examples

Country Status Code Code Definition
AU PC assignment registered
AU PC1 assignment before grant (sect. 113)
CN C41 transfer of the right of patent application or the patent right
CN ASS succession or assignment of patent right
FI PC transfer of assignment of patent
FI PCU new assignee or owner (utility models)
GB PLE entries relating assignments, transmissions, licences in the register of patents
GB S30Z assignments for licence or security reasons
HK AS change of ownership
JP S111 request for change of ownership or part of ownership

As you can see from the above, there’s complexity to recording legal status events. Some codes have English definitions that are almost impossible to interpret to anyone not intimately familiar with the national patent office procedure.

Some legal status codes are frequently used, while others have only been used a handful of times or may even have become obsolete.  A key to divining the usefulness of a code is to look at the “Statistical ranges of legal status data with codes and examples.xls” document from the EPO “Updated Regularly” section of the site.  As of the date of this writing, this spreadsheet was last updated in October of 2012, so it can’t be fully relied upon, but still shows which codes were popular up to that time.   For example, the JP code S111, defined as “request for change of ownership or part of ownership,” had been used only 10 times as of Oct 2012 – this doesn’t inspire much confidence in the completeness of the JP assignment data.  It’s possible the English definition of this code is a misleading translation, or maybe there is a different assignment code that is more frequently used.

Japanese Assignment Data in INPADOC

Country code Legal event code     (PRS code) Code explanation No of records
JP S111 request for change of ownership or part of ownership 10

Because the short English descriptions of legal status codes can sometimes be very vague, the EPO has also begun hosting detailed descriptions of these codes, on its Legal Status Codes pages. Unfortunately, the work of fully defining these codes is difficult, and right now the EPO only has in-depth definitions for codes in Australia, France, Germany, Europe, New Zealand, the UK, the USA. I look forward to more of these descriptions being published, especially for the Asian patenting authorities.
So, the next time you have a legal status question, take advantage of this valuable documentation – and make sure that you tell any EPO staff you come across that we need even more!!


This post was contributed by Landon IP Librarian Kristin Whitman. The Intellogist blog is provided for free by Intellogist’s parent company, Landon IP, a major provider of patent search, technical translation, and information services.

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