A patent only provides protection within the country in which it is granted. Therefore, an inventor must file for a patent in each country where patent protection is desired. Most countries require that nationals file for a patent in their own country before seeking foriegn patent protection. An international treaty, the Paris Convention, allows an applicant to file for a patent on the same invention in other countries and claim the original (priority) filing. When an applicant files on the same invention in multiple countries, these applications and the subsequent publications are collectively known of as a patent family.

A patent family will include all of the publications resulting from filings on the invention. This may include multiple filings from a country because of the different laws countries have defining how an invention may be patented. The filings themselves may claim single or multiple priorities. The filing may claim one or more prior filings related to the filing.

There are four patent databanks for identifying patent families, and each deals with these families differently.

None of these databases provide a complete patent family. Since there are over 170 countries which grant patent protection and INPADOC, which covers the most countries, only covers 60 countries, these databases do not provide a comprehensive survey of patent protection. Also, these databases do not necessarily provide complete coverage for the countries they do cover.

There is also the PatentTracker tool from Minesoft, which offers a current awareness service updating subscribers on new patent family members and status changes within a given patent family, in Europe and North America.

Recent references:
Martínez, Catalina Patent families: When do different definitions really matter? Scientometrics, Volume 86, Number 1 / January, 2011, Pages 39-63


Patent Families in Questel FamPat database

FamPat represents a significant breakthrough in patent family databases.
It provides a comprehensive family coverage of worldwide patent publications published from more than 90 patent authorities: 60 million documents grouped in 40 million inventions with 18 million images.
In FamPat, a single family record combines together all publication stages of the family. Searches for Assignee, Inventor or Classes are conducted on all family equivalents. Boolean searching is available across all family abstracts.

Questel has developed a family definition which incorporates the EPO's strict family rule with additional rules to include: Applications falling outside the 12 month filing limit; Links between EP and PCT publications; Combining US Provisionals that share the same priority with US Published Applications.

FamPat's family definitions also incorporate different patenting authorities' definitions of an invention, particularly useful with Japanese publication searching.

Biblio: Early 19th century for some countries (BE: 1875, CH: 1888, DK: 1895, FI: 1842, FR: 1842, GB: 1840, SE: 1891, US: 1836, etc.) 1920's for other publications.
Full text: Argentina, Austria, Belgium, Brasil, Canada, Chile, China, Denmark, EP, Finland, France, Germany, India, Japan, Mexico, Korea, PCT, Russia, Spain, Sweden, Switzerland, United Kingdom, US (A, B, Old).

1. Use of proprietary, manually built and domain-specific dictionaries, improved by the Lingway linguistic technologies (20 years of experience in the field)
2. Use of a mix of different MT software depending on the type of text to be translated
3. Manual improvement of assignee names
4. Hybrid machine translation (HMT) approach that leverages the strengths of statistical and rule-based translation methodologies
5. MT replaced by human translation as soon as it is available

EPO Classification (ECLA, Dutch and Berlin Classifications)
FI and FTerms (Japanese Classifications)
International Patent Classification (IPC)
USPTO Classification

Laetitia Aymonin
Communication Manager
laymonin [at] questel [dot] com

March 4th, 2010


Patent families in EDOC

EDOC was the online, patent family information file distributed by INPI, The French Patent & Trademark Office. It has been replaced by FamPat by Questel as explained in Pierre Buffet's comment below. The original entry by Michael P. O'Hara in 1998 is available via the page history function for this page using the Info link in the upper right corner icon.


Patent Families in Derwent World Patent Index (DWPI) database

Thomson Reuters uses a unique process to create the patent families within Derwent World Patents Index (DWPI). This process uses expertise developed over more than 40 years to create patent families whose members have matching technical content. The priority details of new documents are first analyzed against those already in DWPI. Patents with priority details not seen before are termed 'Basic', for which a new family is created within a new DWPI database record. New patents with priority data matching that already found within an existing DWPI record are termed 'Equivalent', and the patent becomes a new family member within that DWPI record. Special cases are catered for, e.g. continuation-in-part patents are given a new DWPI record to reflect the additional technical content, and cross-referenced back to the original.

The patent family process that creates DWPI also flags-up potential 'non-convention equivalents' - these are patents with the same technical content as an existing DWPI family, but not claiming the same priority. When a match to an existing record is found, the non-convention equivalent patent is added into the DWPI record, and marked with a # symbol to indicate this special status. This is important extra information for DWPI users, as it allows the easy identification of additional patents that describe the same invention. More than 200,000 DWPI records contain non-convention equivalents. 

Bob Stembridge
Customer Relations Manager
Thomson Reuters
bob.stembridge @ thomsonreuters.com

February 3, 2009


Patent Families in INPADOC

The priority numbers and application numbers are used for establishing the family links. Priority is necessary to determine patent families, so coverage starts with the availability of priority information. The coverage varies from country to country. Documents are linked to a family even when they have only one priority in common. Further iterative searches are conducted for patents with priorities similar to those of any family member of the initially built family. Thus, the family members do not necessarily have a single priority in common with the one you searched for initially. For example: Document A has priority 123, Document B has priority 123 and 456, and Document C has priority 456. All three would be included in the family. The application number is necessary as sometimes in follow up publications (divisions, continuations, additions) there is no reference to the priorities given in the basic document. "Technical" families were found by analysis of inventor names and applicant names; the "priority" link is established manually by allocation of a fictitious priority number to the family members. This is done only for those cases investigated by the EPO search team.

A ready source of INPADOC data is Esp@cenet. The results pages for individual patent documents usually include a tab for Bibliographic data with a "View INPADOC patent family" link and a tab for INPADOC legal status. Many online services also provide INPADOC data.

Compiled from information provided by Peter Paris of the European Patent Organization.

January 20, 1999


Patent families in the CAS Databases

Patent family information for chemical and chemical engineering patents from 1957 to the present is available in the CAplus database on STN. For each CAplus "basic" patent, i.e., the patent document abstracted and indexed by CAS, CAS has identified other closely related patent family members. Closely related patent family members tend to have simple priority relationships with the basic patent, such as citing the same priority application. While most patent families consist of closely related patents "covered" by the same abstract, there are some cases with more than one abstract associated with a patent family. This may happen when related patents have somewhat different technical content or when family members have more complex relationships such as multiple priorities from different countries or relationships resulting from division, continuation, or continuation-in-part patents. Such extended patent family relationships are also identified in the CAplus database.

Eric Shively
CAS Public Relations Group Leader
eshively @ cas.org

October 17, 2008


  1. This compilation of patent family information was originally created in 1999, and it covers resources that were available at that time. One of the databases listed is EDOC, produced by INPI and available at the time on Questel.  The EDOC data was folded into Questel's PlusPat/FamPat file and is no longer available as a free-standing file.

    Can someone confirm whether INPI is still producing the database, and if so, where the data is available?

    1. Edlyn,

      Allow me to answer to your accurate question. The EDOC EPODOC PLUSPAT FAMPAT databases represent a continuous evolution. No, there is no reason to continue the EDOC file for the following reasons:

      1. "Once upon a time", INPI asked EPO to provide - beyond the registry - their files INVE (inventory), PRIOR (all applications having one priority) and ECLA (the now well known classification used by the EPO) in order to build new databases on Questel.

      It is how EDOC is born: database very poor including "just" Application, Priority and Publication numbers together with the ECLA codes (as well as ICO, IDT, ...). No title, no Applicant, no Inventor... It was the "image" of the EPO documentation in The Hague.

      2. When EPOQUE started (1989), Questel was asked to build an improved database "EPODOC", which was EDOC + titles, abstract, inventors and applicant. Still one record per application. To a certain extent, it is the file which is on Espacenet and which was the foundation of DocDB. In parallel, these files have been consolidated with the Inpadoc route, mainly for bug fixing.

      3. On the same model, Questel built PlusPat, which then has been improved with other sources.

      4. After a thorough analysis of the various family systems (Derwent, EPO "strict" family, Inpadoc extended family), Questel decided to built its own family system with the axioms:

      • to be as close as possible to the concept of invention,
      • to be fully automatic,
      • to be dynamic (recomposed families, e.g. US application claiming JP priorities can generate a merger of the previous 3 JP records).

      Lastly, it is important to keep that the various families can co-exist: the FamPat family is tailored for searching while the Inpadoc family is interesting for displaying related inventions.

      I hope this answers your question.


  2. Pierre,

    Thank you for providing the background information.  However, your last comment ("...the FamPat family is tailored for searching while the Inpadoc family is interesting for displaying related inventions.") interests me.

    Would you provide some additional explanation as to why FamPat is tailored for searching?

    Thank you in advance.

    Best regards,

    Jason Newton

    1. Jason,

      The FAMPAT Family being closer to the concept of invention, it means that you search a database of inventions, each invention being described by all elements of the various members of the family. This allows a better recall as all data elements are merged in a single record.

      The INPADOC family is broader as it includes all records having at least one priority in common. This means that you can end with family members which are related but which do not describe the same invention. A consequence is that searching INPADOC families on a specific topic can generate false drops. For instance, have a look at the Inpadoc family that includes:

      WO2004110608 - Scalable continuous production system

      WO03043730 - Enhancing fluid flow in a stacked plate microreactor

      WO200189681 - Modular chemical production system incorporating a microreactor

      EP1123734 - Miniaturized reaction apparatus

      Best regards,