Can I legally use an expired patent?

Generally, yes. Once a patent expires, no one can be sued for infringing it, so anyone can make, use or sell what it describes. Check two things first: that it really expired and was not reinstated, and that no other patent still in force covers part of your product.

Can I patent an expired patent?

Not the same invention. An expired patent is public prior art, so the idea it describes can never be patented again. You can patent a new, non-obvious improvement on it, such as a different mechanism, material, or use.

How long does a US patent last?

A utility patent lasts up to 20 years from its earliest US non-provisional filing date, sometimes extended for USPTO delays. It only lasts that long if the owner pays maintenance fees at 3.5, 7.5 and 11.5 years after grant. Design patents filed since May 13, 2015 last 15 years from grant and have no maintenance fees.

Can an expired patent come back?

A patent that expired for an unpaid maintenance fee can be reinstated if the owner petitions the USPTO and shows the delay was unintentional. A patent that reached the end of its full term cannot. Check the record again before you invest, and keep evidence of when you started.

What is the difference between an expired and an abandoned patent?

An expired patent was granted, then its protection ended, either at the end of its term or because the owner stopped paying maintenance fees. An abandoned patent application was never granted: the applicant stopped responding to the USPTO or chose to drop it.

Where can I find a list of expired patents?

The USPTO and Google Patents hold the records, but they show legal events rather than plain-English descriptions. AutoInvent surfaces expired and abandoned patents with a plain summary, the drawing, and the reason protection ended, so you can judge an opportunity in seconds.

Protection ended. The ideas are still good.

Expired patents
you can build on.

Real US patents whose protection has ended, each explained in plain English. See what they do, why they lapsed, and how to turn one into an invention of your own.

Browse expired patents How to check a patent expired

From the AutoInvent library

Expired patents worth a second look

Each of these was granted, then lapsed when its owner stopped paying USPTO maintenance fees. Open any one for the full summary, the drawing, and the legal record behind its status.

ExpiredFiled 2018Food

Squeezable warm liquid chocolate dispenser

This is a container designed to dispense chocolate.

US11224233B2

ExpiredFiled 2015Business & commerce

Scan and order app for local shops

This invention describes a system for ordering products or services using a mobile app on a device equipped with a scanning lens.

US10373223B2

ExpiredFiled 2018Computing

Head-tracked sound guiding to a real spot

This invention describes a system that helps a person move to a specific spot in a real-world space.

US11055913B2

ExpiredFiled 2017Data recognition

Drone crowd behavior monitor and automated response

This system uses a drone flying over a crowd to take pictures and videos.

US10706289B2

ExpiredFiled 2018Food

Solid chocolate press dispenser

This system is a manual chocolate dispenser.

US11064712B2

ExpiredFiled 2015Computing

Twisting phone with a split screen

This invention describes a mobile phone or tablet with a display that's split into two parts.

US10564675B2

ExpiredFiled 2015Optics

Zooming phone camera with automatic distortion fix

This invention describes a camera module for mobile phones that can switch between wide-angle and normal-angle views.

US10791274B2

ExpiredFiled 2019Audio

Fabric mic for clear voice, removing echo

This invention describes a system for voice communication that uses a microphone hidden inside a piece of fabric, placed between its outer and inner…

US10706871B2

ExpiredFiled 2019Data recognition

AI fire spotting by satellite and drone

This system detects fires by first scanning wide areas with satellite images, using a specialized AI (a convolutional neural network) to pinpoint…

US11182611B2

ExpiredFiled 2017Medical devices

Radar that reads your feelings

This is a tiny radar system designed to detect emotions.

US10159435B1

ExpiredFiled 2017Clothing

Cooling/warming clothing with angled branched tubes

This invention describes a temperature-regulating garment that uses a network of tubes embedded within channels in its fabric.

US10980292B2

ExpiredFiled 2020Wireless

Automatic 5G frequency switching for best signal

This invention describes a system that helps 5G devices get the best possible wireless connection by optimizing their access to different parts of the…

US11153762B1

ExpiredFiled 2020Business & commerce

AI that learns what items you like

This invention describes a system that learns what items to recommend to users by studying their past interactions with an electronic catalog.

US10896459B1

ExpiredFiled 2016Industry & transport

Paper coating for ink that sticks better and looks sharp

This invention describes a special coating for paper or other surfaces that helps ink stick better and look sharper when printed.

US10589559B2

ExpiredFiled 2019Consumer & health

Teaching robots to draw shoe sole lines

This invention describes a system to automate a step in shoemaking by recording how a person manually draws a gaging line on a shoe, which is the…

US11172734B2

See 1,700+ more expired patents

Statuses come from each patent's USPTO legal-event record. A lapsed patent can occasionally be reinstated, so confirm the current status before you build on one.

Know what you're looking at

Expired, lapsed, or abandoned?

In all three, no one holds enforceable rights to the idea today. They got there in different ways, and that changes what you should check.

Status	What happened	Can it come back?
Expired (full term)	The patent ran its full life: up to 20 years from filing for a utility patent, 15 years from grant for a recent design patent.	No. The invention is permanently in the public domain.
Expired (lapsed)	The patent was granted, but the owner stopped paying the maintenance fees due 3.5, 7.5 and 11.5 years after grant.	Sometimes. The owner can petition to reinstate it if the missed payment was unintentional.
Abandoned	The application was never granted. The applicant stopped responding to the USPTO or dropped it on purpose.	Sometimes. An abandoned application can be revived by petition, though most never are.

Looking for applications that were never granted? Browse abandoned patents.

Before you build

How to check a patent really expired

Four checks, about ten minutes, and you will know whether an idea is actually open.

Do the term math

Find the filing date. A utility patent filed more than 20 years ago has almost certainly reached the end of its term, unless it received a term adjustment for USPTO delays. The patent expiration checker does this math, and checks 2 and 3, for you.

Read the legal events

On Google Patents, scroll to "Legal events". A line such as "lapse for failure to pay maintenance fees" means protection ended early. Fee payments with no lapse mean it may still be live.

Confirm with the USPTO

Look the number up in USPTO Patent Center and its maintenance fee records. Watch for a later reinstatement, which would make the patent enforceable again.

Look for newer patents nearby

An expired patent frees its own claims, not every improvement built on it since. Search for recent patents in the same space before you sell a product.

From old patent to new invention

You can't re-patent it. You can improve it.

An expired patent is public prior art, so the original idea can never be patented again. A new, non-obvious improvement can. That is where AutoInvent comes in.

Find one worth reviving

Browse expired and abandoned patents in plain English, filtered to the fields you know.

Reinvent it with AI

Get modern improvement directions, then check how original your version is against existing patents.

File a provisional

Lock in your filing date with a USPTO-ready provisional patent application, no lawyer required.

Expired patents
you can build on.

Expired patents worth a second look