Key Takeaways

  • Expired patents can present valuable opportunities for innovation or commercialization.
  • Buying an expired patent typically involves confirming ownership, checking reinstatement status, and negotiating with the original holder.
  • Expired or abandoned patents may be available for public use, but due diligence is essential to avoid legal pitfalls.
  • The USPTO and third-party databases can help identify expired patents and assess their status.
  • Legal assistance is recommended when drafting or reviewing purchase agreements or reassignment filings.

If you're wondering how to buy expired patents, you will be pleased to know that this is not an impossible task. You will, however, need to perform due diligence in order to legally protect you and your company. If you have recently conducted a patent search and would like to move forward, here is what you need to know.

USPTO Patent Maintenance Requirements

Once a patent is approved, it needs to be renewed. After 4, 8, or 12 years, if fees are not paid to the United States Patent and Trademark Office (USPTO), the patent will expire.

These maintenance fees are due before 3.5, 7.5, or 11.5 years have passed. There is also a six-month "grace period" — which requires an additional $150 be paid in addition to the standard fees.

If an owner does not pay for renewal, patents can only be reinstated if that individual or company pays a significant surcharge fee. They will also likely need a legitimate reason for allowing that patent to expire. This will be in the form of a petition.

Although patents do get reinstated, there are three expiration tranches that dictate resulting fees for large entities. Smaller entities typically pay half the following amounts:

  • E1 — up to $1,130
  • E2 — up to $2,850
  • E3 — up to $4,730

It is important to note that although U.S. design and plant patents expire after 14 years and 20 years respectively, they do NOT require maintenance fees.

Patents will typically expire for one of two reasons:

  • Failure to pay any required maintenance fees, depending on the type of patent in question
  • Natural completion of the patent's term

What will happen when somebody uses or makes an invention whose patent has expired will depend on the nature of the expiration.

Is There a Way to Buy Expired Patents?

When wondering if it's possible to buy an expired patent, know that not everything can be patented, which is fundamental to the patent system. For example, if a technology is already considered to be "public domain," a company or individual cannot patent it. There are numerous circumstances where this is the case.

  • When something has already been around throughout history — such as oxygen or pears.
  • Alternatively, an invention can be released into public domain without a patent and thus are no longer patentable. An example would be the wheel or Salk's polio vaccine.
  • An existing patent may have also expired, which is the case for the telephone.

When you submit an application to patent something that's similar to an invention with an expired patent, you'll need to sign an oath that states you are the item's inventor. The patent examiner assigned to your case would otherwise locate the original patent very quickly and deny your patent application.

If you would like to purchase an expired patent, this IS possible. In order to do so, you must first contact the patent owner or the attorney on record for that patent.

Steps to Purchase an Expired Patent

While expired patents usually fall into the public domain and are free to use, there are cases where you may still want to buy them—especially if there's a possibility the patent may be reinstated or it still holds market value. Here’s how to proceed:

  1. Verify Expiration Status:
    Use the USPTO’s Public PAIR system to confirm whether the patent is expired, abandoned, or still enforceable. An expired patent may still be within the window for reinstatement.
  2. Identify the Patent Owner:
    Check USPTO records to find the current assignee. If the ownership has changed, it may require deeper research using assignment databases or legal tools.
  3. Determine Reinstatement Risk:
    Just because a patent is expired doesn’t guarantee it's permanently out of enforcement. Patents can be reinstated under specific conditions (e.g., unintentional nonpayment of maintenance fees), potentially making your use infringing. Consulting a patent attorney is wise here.
  4. Initiate Contact:
    If you wish to own the rights or if the patent can be reinstated, contact the patent owner or their legal representative to discuss a potential sale or reassignment.
  5. Negotiate the Terms:
    Agree on price, licensing rights (if applicable), and conditions of use. In some cases, you may only need a non-exclusive license instead of a full assignment.
  6. File a Patent Assignment:
    Once the purchase is agreed upon, file a patent assignment with the USPTO to officially record the transfer of ownership.

How to Use Expired or Abandoned Patents Instead of Re-inventing

To begin, head over to the U.S. Patent Full-Text Database Manual Search. Search by filing date, inputting either one specific date or a range of dates. This will allow you to access patents on the invention you are creating. You can also make use of search engines such as Google's Patents Advanced Search features if you need to narrow your search results to patents that have been filed 20 years ago or more. You will then need to:

  • Copy the patent number or publication number.
  • Go to the USPTO Public Pair portal and perform a search. This will allow you to check the status of a patent — being either patented, expired, or abandoned.

It's worth noting that abandoned and expired patents are considered to be a part of the public domain. In other words, patents that fall into this category are free and open to use by the general public. Patents are considered to be abandoned in the event that the original inventor "gives up" at any point during the process of applying for a patent, decides not to continue to pay required fees, and so on.

Benefits of Acquiring Expired Patents

Buying an expired patent—even one that's lapsed into the public domain—can provide several advantages:

  • Freedom to Operate:
    Confirming the expired status removes fear of infringement while allowing you to commercialize an innovation.
  • Market Entry Leverage:
    Owning a once-patented innovation gives you a strategic story, especially for marketing or seeking funding.
  • Portfolio Expansion:
    Expired or abandoned patents can be bundled with other intellectual property assets to increase your portfolio’s value.
  • Insight into Innovation:
    Expired patents offer insight into past R&D that may inspire further improvements or modern adaptations.

What Are Patents?

Before you take that initial step to buy expired patents, it is important to understand how this process will benefit your invention or idea. Put simply, a patent ensures that only you can profit from your unique invention.

Only when you give others permission are they able to manufacture or sell what you have invented. To better address your needs, there are three patent options available. In most cases, these are non-renewable.

  • Plant Patents — These patents protect new vegetation or hybrid plants and are good for 20 years.
  • Design Patents — If you have reinvented an existing product in a way that is innovative and creative, you'll need a design patent. These last for 14 years.
  • Utility Patents — Pretty much everything else falls into this category, including new machines, software, processes, etc. These also last for 20 years.

Under normal circumstances, a patent can't be renewed. Patents are intellectual property rights that have been granted by the United States Patent and Trademark Office. While it's not required that you patent your inventions, there are certain advantages associated with doing so. Holding a patent provides your unique inventions and ideas with a certain measure of legal protection that you wouldn't otherwise be able to enforce.

Common Reasons Patents Expire or Are Abandoned

Understanding why patents expire can help you assess the viability of buying or using one. The most common reasons include:

  • Nonpayment of Maintenance Fees:
    Especially for utility patents, fees must be paid periodically to maintain enforceability.
  • Natural Expiration:
    Patents reach their full term—usually 20 years for utility and plant patents, and 15 years for design patents.
  • Abandonment:
    The owner may stop pursuing a patent before it is granted or simply let it lapse due to lack of commercial interest or resources.
  • Rejection and Non-Response:
    If the USPTO rejects a patent application and the applicant does not respond or appeal, the application becomes abandoned.

Exceptions in Patent Expiration

The one exception that exists when it comes to patent expirations pertains to patented pharmaceutical innovations. In the event that pending approval from the Federal Drug Administration hinders marketing efforts, Congress will sometimes extend the product's patent expiration date. Under normal circumstances, the length of the extension will be equal to the length of the delay in question. However, Congress has the final say on exactly how long they will grant an expiration extension for.

Patents pertaining to pharmaceutical inventions may also expire sooner than 14 to 20 years in the event that the inventor fails to pay required maintenance fees during the course of the patents life.

Effects of Patent Expiration

In most cases, a patent will expire 20 years after the date that they were originally filed. Simply put, this means that if an invention is more than 20 years old, it's most likely available for the general public to make, use, copy, or modify without having to worry about being in violation of an existing patent. However, it's never a good idea to just assume that this is the case. You should always take steps to make sure you're not violating another inventor's legal patent.

When patents expire, any legal protections that they offered during their term cease to exist. That doesn't mean that expired patents aren't without their uses, however. For example, patent owners still have the right to sue for any past infringements that might have occurred before the patent in question reached its expiration date. This also means that if you purchase an expired patent, the right to pursue legal action for past infringement is transferred to you as the new owner.

If you are considering the possibility of pursuing legal action for past infringement, though, it's worth noting that this is only an option if the infringement in question occurred within six years before the date you file your lawsuit.

When patents do expire, they essentially cease to exist. This normally works to the consumer's benefit, due to the fact that others are now free to reproduce and sell the patented invention. Ultimately, this should lead to greater availability as well as a higher degree of product variation on the open market. Perhaps the biggest benefit that can come out of a patent's expiration is that the more people there are manufacturing and selling a particular product, the more the price for that product is driven down in the market.

When a patent expires on something you originally invented, you're still free to continue producing and sell it. Keep in mind, however, that buyers may not be as eager to pay your original cost as they were when you were the only person in the world that could offer it to them. When a patent expires, it creates price competition. And the more your invention gets picked up by other manufacturers, the less expensive it's going to become over time.

One benefit for you as the original inventor is that nobody else can market your invention under the same name you originally gave it. They'll have to devise their own product names and descriptions if they wish to begin producing and selling your creation.

Legal Considerations When Buying Expired Patents

Although expired patents generally cannot be enforced for future infringement, some legal nuances should be considered:

  • Past Infringement Rights:
    Purchasing an expired patent may give you the right to sue for infringement that occurred before its expiration (within six years).
  • Reinstatement Possibility:
    If a patent is within its reinstatement window, purchasing it can be a strategic move to revive and enforce it—pending approval by the USPTO.
  • Assignment Validity:
    Ensure proper legal documentation is in place. An invalid or poorly executed assignment can render your claim unenforceable.
  • Freedom-to-Operate Analysis:
    Other overlapping patents may still be active. Conduct a full patent clearance search before bringing a product to market.

If you are considering how to buy expired patents or enforce rights related to them, connecting with an attorney on UpCounsel can help ensure your transaction is valid and strategic.

Frequently Asked Questions

  1. Can I legally use an expired patent?
    Yes, once a patent has expired and is not eligible for reinstatement, its contents fall into the public domain and can be used freely.
  2. Can expired patents be reactivated?
    Yes, under certain conditions (e.g., unintentional lapse), expired patents can be reinstated if fees are paid and a petition is accepted by the USPTO.
  3. How do I find out if a patent is expired?
    Use the USPTO's Public PAIR system or Google Patents to check the status and history of the patent.
  4. What should be included in a purchase agreement for an expired patent?
    It should outline the patent details, price, terms of transfer, any limitations or warranties, and the effective date of the assignment.
  5. Is buying an expired patent the same as buying an active one?
    No. Active patents offer enforceable rights, while expired patents generally don't unless reinstated. The strategic value and legal process can differ significantly.

If you are wondering how to buy expired patents, you can post your legal need on UpCounsel's marketplace. UpCounsel accepts only the top 5 percent of lawyers to its site. Lawyers on UpCounsel come from law schools such as Harvard Law and Yale Law and average 14 years of legal experience, including work with or on behalf of companies like Google, Menlo Ventures, and Airbnb.