Why Patent Citation Matters

Patents document inventions with legal precision. Citing them correctly establishes prior art in technical fields, credits inventors properly, provides reproducible references (patent numbers are permanent), and demonstrates thorough research in IP-heavy fields.

Key Information to Gather

For any patent citation, collect the inventor name(s), the patent title, the patent number (including country prefix), the patent office or country, the issue or publication date, and optionally the URL or database.

Patent number formats vary by country:

• U.S.: US 10,123,456 or US10123456B2

• European: EP 1234567

• International (PCT): WO 2023/123456

• UK: GB 2345678

Quick Reference by Major Style

APA (7th Edition):

Inventor, A. A. (Year). Title of patent (Country Patent No. 123456). Patent Office. URL

Example:

Chen, L., & Park, S. (2023). Method for neural network optimization (U.S. Patent No. 11,234,567). U.S. Patent and Trademark Office. https://patents.google.com/patent/US11234567

In-text: (Chen & Park, 2023)

MLA (9th Edition):

Inventor Last, First. Title of Patent. Country Patent Number. Date.

Example:

Chen, Li, and Sarah Park. Method for Neural Network Optimization. US11234567B2. 15 Mar. 2023.

Chicago:

Inventor Last, First. Title of Patent. Country Patent number, filed Month Day, Year, and issued Month Day, Year.

IEEE:

A. A. Inventor, "Title of patent," Country Patent number, Month Day, Year.

Patent Applications vs. Granted Patents

Granted patents have been reviewed and approved. Cite these when possible—they're the final, authoritative version.

Patent applications are published but not yet granted. They may be abandoned, rejected, or modified. If you must cite an application:

Inventor, A. A. (Year). Title (U.S. Patent Application No. 2023/0123456).

Note that it's an application, not a granted patent.

Finding Patent Information

Google Patents: Free, searchable, citation-formatted. Good starting point.

USPTO (U.S.): Official source for U.S. patents. https://www.uspto.gov

Espacenet: European Patent Office database covering worldwide patents.

WIPO PATENTSCOPE: International PCT applications.

Each database provides full patent documents and citation information.

Multiple Inventors

Patents often have many inventors. Include all of them:

Chen, L., Park, S., Johnson, M., & Williams, R. (2023). Title (U.S. Patent No. 11,234,567).

For very long inventor lists (10+), check your style guide—APA allows "et al." after the first 19 authors.

International Patents

For non-U.S. patents, use the appropriate country code and office:

Yamamoto, K. (2022). Title of patent (Japanese Patent No. JP6789012). Japan Patent Office.

For PCT (international) applications:

Inventor, A. A. (Year). Title (Patent No. WO 2023/123456). World Intellectual Property Organization.

Patent Families

A single invention may have patents in multiple countries (a "patent family"). Cite the most relevant one—typically the country where the work was conducted or where readers are likely to access it.

If the patent family itself is relevant, note it:

Chen et al.'s neural network optimization method is protected by a patent family including U.S. Patent No. 11,234,567 and European Patent No. EP3456789.

Citing Specific Claims or Figures

Patents are divided into numbered claims (the legal protection scope) and often include figures. Reference these specifically:

In-text: (Chen & Park, 2023, Claim 12) Or: (Chen & Park, 2023, Fig. 3)

Assignees vs. Inventors

Inventors are the individuals who created the invention. They're your "authors."

Assignees are the entities (usually companies) that own the patent rights. You might mention them in text:

Chen and Park (2023), assigned to TechCorp Inc., describe a method...

But cite inventors as authors.

The exact formatting for patent citations depends on your required citation style. Check the specific guide for your discipline below.