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Patent classification helps conduct searches

The patent classification is a way of defining the technical field of an invention. At present, the two most popular patent classification systems are the International Patent Classification (IPC) and the Cooperative Patent Classification (CPC).

The patent classification helps you to conduct searches in our databases. The classification allows you to restrict your search to a particular technical field and to keep the number of search results at reasonable level.

International Patent Classification (IPC)

You can use the International Patent Classification (IPC) in all our databases. The IPC classes are indicated on the front page of each patent document with the marking Int.Cl. (2015.01)". The number in brackets varies and tells you the IPC version of the classification.

The IPC classification is updated once a year. Old classification schemes can be found on the IPC website. Go to the IPC websiteOpen link in a new tab. (Under "CatchwordsOpen link in a new tab" you will find a small list of search words that you can use to try to find suitable classes.)

Go to the WIPO website for more informationOpen link in a new tab. (World Intellectual Property Organization WIPO)

Read more about the IPC and classification rules in English: Guide to the IPCOpen link in a new tab.

Cooperative Patent Classification (CPC)

You can use the CPC classification system instead of the International Patent Classification (IPC) in database searches. In the Espacenet database, for instance, there is a specific field for the CPC.

The use of Cooperative Patent Classification (CPC) based on the IPC classification has grown in popularity, particularly among large offices. For information seekers, the CPC provides a precise and usable search tool. As the IPC offers a complete range of technical fields divided into more than 70,000 groups, the CPC divides the fields into 250,000 groups, which is why the search result is more precise than when using the IPC.

The CPC is a system jointly maintained by the European Patent Office (EPO) and the US Patent Office (USPTO) and many national patent offices, including the PRH, classify their patent documents using the CPC. In addition, the EPO classifies the patent documents of countries included in the minimum documentation, as referred to in the international Patent Cooperation Treaty (PCT), by the CPC. Such countries are Germany, France, United Kingdom, Switzerland, Russia, Japan, Australia and Canada (and PCT documents). Since not all patent documents have been classified using the CPC, you might not find all relevant information when searching with the CPC. In contrast to the IPC, the CPC does not indicate the classification code in the patent documents, and therefore the CPC can only be used in online searches.

Read more about Cooperative Patent Classification (CPC)Open link in a new tab

Printable version Latest update 05.11.2021