Newly resurfaced data from the United States Patent and Trademark Office revealed that more than 1.4 million patent assignment records were inadvertently kept from the public for years, raising concerns about the reliability of the patent ownership system and the risks facing companies that relied on incomplete records. Researchers at Richardson Oliver Insights discovered the issue after the USPTO temporarily paused assignment data updates earlier this year and later republished historical records containing hundreds of thousands of previously hidden ownership transfers, including thousands involving issued patents. Experts warned that missing assignment data can create major problems in patent transactions, licensing deals and litigation because buyers and investors may unknowingly rely on inaccurate ownership information. Some patents even appeared to have multiple undisclosed transfers to different owners, potentially opening the door to disputes over who actually controls valuable intellectual property rights. Industry observers say the incident highlights broader concerns about the USPTO’s database governance and could reignite calls for mandatory patent assignment recording requirements.