If a patent number cannot be found on the USPTO website itself, is it expired?

The below does not constitute legal advice, does not form an attorney-client relationship, and should not be relied upon to take or refrain from taking any action.

The presence or absence of a patent on the USPTO website is an indicator only of an error on the website of some kind, not that the patent is expired. Another item to keep in mind is that design patents are essentially only figures, but that should not stop the brief text of the patent from appearing. Below is a link to a design patent issued in 1980 as an example.

Mr. Adams correctly notes the term of a design patent is 14 years from issue, so a filing date of 1980 probably means it is expired, as it would be highly unusual for a design patent to be pending for 15 years.

One additional note. There are no maintenance fees for a design patent. When searching for a design patent, you might have to enter a "D" prior to the number on the patent, depending on the database used for your search.

Issued patents are public record, even after they have expired, so you should always be able to look up a reference at the PTO. The best way to determine if a patent is still enforceable is to look it up at the PTO website (www.USPTO.gov). Other internet resources may not be up-to-date, or may simply be inaccurate. Companies commonly confuse "patent pending" with having an issued patent, and may even incorrectly claim that they have a patent.

Additionally, the term for patents is generally 20 years from the FILING DATE. Design patents last 14 years from when they are ISSUED. However, patents may expire before then if maintenance fees are not paid, so be sure to check the status as well instead of simply relying on the filing or issue dates.

Issued patents are public record, even after they have expired, so you should always be able to look up a reference at the PTO. The best way to determine if a patent is still enforceable is to look it up at the PTO website (www.USPTO.gov). Other internet resources may not be up-to-date, or may simply be inaccurate. Companies commonly confuse "patent pending" with having an issued patent, and may even incorrectly claim that they have a patent.

Additionally, the term for patents is generally 20 years from the FILING DATE. Design patents last 14 years from when they are ISSUED. However, patents may expire before then if maintenance fees are not paid, so be sure to check the status as well instead of simply relying on the filing or issue dates.