Frequently asked questions




What are the expected benefits of CPC?

Through the implementation of CPC, the USPTO and the EPO believe that applicants and the user community will derive many benefits. Once fully implemented, the Offices anticipate CPC will:

  • Enhance examination efficiency;
  • Improve access to more documents from patent offices around the world;
  • Improve navigation and understanding of a single classification system;
  • Facilitate worksharing on patent applications filed in multiple IP offices;
  • Improve consistency of classified search results across IP Offices; and
  • Provide adaptive and actively maintained classification schemes.


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What will CPC look like?

The CPC scheme will be aligned with WIPO format and specifications for IPC. The goal is to allow for the potential incorporation of the CPC symbols into the IPC at a later stage if desired. To see how the scheme will look like, you can consult the section Deliverables.


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How will the transition be made from ECLA/USPC to CPC?

The migration to CPC will mean substantial changes affecting the work of patent examiners. In addition, CPC will change the source of patent classification information for users and stakeholders of the EPO and USPTO.

To ensure a smooth transition, the EPO and USPTO are reaching out to inform and seek input from our user community and examination staff throughout the process.

To address the many details throughout this transition, the Offices are working closely together to establish training and a robust quality management system.


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Who will be in charge of maintaining the classification and further develop it?

The CPC will be co-owned by the EPO and USPTO. It is envisaged that there will be a multi-year planning system for identifying areas requiring reclassification which will involve examiners from both offices and, once agreed upon, the work will be shared between the two offices.


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How often is the CPC scheme expected to be revised?

It is expected that there will be multiple revisions in a year. A multiyear plan will be established beforehand.


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How often will a new version of CPC be released and will there be version numbers?

It is envisaged that revision will be take place more quickly than is the case with IPC. The exact frequency of revisions is not yet known, but it is most likely that there will be multiple revisions per year. Each version will have a version date.


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When a revision process takes place, when will the revised scheme be made available?

The EPO and the USPTO have agreed that it will be decided on a case by case basis whether the revised scheme will be published before or after the reclassification work has been completed.


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What are the so-called CPC definitions?

The CPC definitions contain additional information prepared by EPO classification experts in each technical field. In the CPC definitions, explanations on the classification practices are compiled for the technical field concerned. These definitions will be used for training on CPC.


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How will harmonization of classification between the two offices be ensured?

A quality assurance system will be put in place to ensure that the classification symbols allocated by both offices are in accordance with the rules for classification compiled in the CPC scheme and the CPC definitions.


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In which language will CPC be?

As with ECLA and USPC, CPC will be available in English. There are currently no plans to provide the scheme in other languages.


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How much bigger than ECLA will the CPC scheme be?

As CPC will incorporate ICO (In Computer Only) indexing codes and some KW (Keyword) codes, the current 140 000 ECLA entries are expected to grow to some 200.000 entries.


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Will US documents be classified in CPC?

Until now, the EPO has classified the vast majority of US documents into ECLA. These ECLA classification symbols will be converted into CPC symbols. The offices are making a coordinated effort to classify into CPC the remaining US documents that had not been classified into ECLA.


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