International Patent Searching

To search international patents by class, first identify an international patent classification that corresponds to a US Patent class and subclass. We have a paper concordance in the Patent Center (608.773 C7419) or you can find one on the PTO’s web site.

  1. Go to
  2. Under patents, click on search, click on Tools to Help in Searching Patents by Classification.
  3. Under A1, type in a class and subclass and select U.S. to IPC Concordance and click on submit.
  4. Jot down the IPC number such as b60j1/20 (no space)
  5. Go to
  6. Click on Advanced Search.
  7. Type in the IPC classification on the last line and click on search.
  8. Click on a patent number for more information on a patent. The amount of information varies from patent to patent. Some patents are complete with drawings and claims. Others have only abstracts and many have no information. You can choose from a list of options (if available) on the top of the screen.
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