Patent Ownership: How to Find Who Owns a Patent

Quick Reference — This article is a short, high-density reference. For deeper coverage see the linked articles below.

Knowing who owns a patent is essential for licensing negotiations, FTO analysis, and enforcement. Patent ownership is public record — but patents change hands through assignments that may not be recorded promptly.

Step 1: Check the Patent Office Assignment Database

USPTO: Go to assignment.uspto.gov and search by patent number. The most recent recorded assignee is the current owner of record.

EPO: The European Patent Register (register.epo.org) shows the patent proprietor. For validated national patents, check each national register separately.

CNIPA: The Chinese patent register shows the current patentee through CNIPA's online system.

WIPO: For PCT applications, PATENTSCOPE shows the applicant at each national phase entry.

Step 2: Check for Unrecorded Assignments

Assignments are not always recorded promptly. If the listed owner is a company that has been acquired, merged, or dissolved, search company records (SEC filings, Companies House, corporate registries), acquisition announcements, and bankruptcy filings to trace ownership changes.

Step 3: Contact the Owner

Reach out through their patent attorney (listed in the prosecution file at the patent office), their corporate IP or business development department, or through direct outreach.

Sources

1. USPTO — Patent Assignment Search — Official US patent assignment database for identifying current owners
2. EPO — European Patent Register — European patent ownership and legal status information
3. Google Patents — Free patent search with assignee information
4. Lens.org — Open patent database with ownership and citation data