Penn State University Libraries - Patent Number Searching

Although patent numbers are often displayed in products or packaging, patent searchers will also encounter patent numbers regularly as they investigate "non-patent" literature, such as scientific and technical reports. Patent numbers are also commonly available and accessible when gathering information about products available for sale or use in industry.

A good strategy for an inventor trying to determine likely markets for his or her invention includes carefully investigating products similar to one's own invention that already exist. Determine differences and similarities between these and your own product. Be sure to note any and all patent numbers shown on the product, its packaging, or on any literature describing these items.

• Searching by Patent Number (video opens in a new window)

Going Further with a Known Patent

The USPTO organizes all patents into the U.S. Patent Classification System. This system is an important tool for searching patents that relate to specific subject matter or share certain features in common.

When accessing a patent using the patent number, the final result of this search will be a display of patent information. Part of the display, the “Current U.S. Class," is at least one pair of numbers separated by a slash (/). For example, the pairs of numbers in 280/609, 473/614, or 280/5.507 represent a class and a subclass which together form a classification.

Each classification represents a group of patents that share certain features, as set forth by the classification system. Most classifications have 50 to 300 patents. If your patent number is connected to a patent closely related to that for which you are searching, it is likely that the classifications of the patent will help to identify additional patents that are closely related as well.

For more information about classifications and how to use them for searching, see Classification Searching.

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