You've found a product that looks like a winner. Maybe it has a clever folding mechanism, or a shape you haven't seen on other stores. Before you list it, a practical worry comes up: has someone already patented this?
You can check, and you don't need a law degree to do a solid first pass. This guide walks through the steps in order, from spotting clues on the product itself to searching official databases, confirming whether a patent is still active, and deciding what to do if you find something similar. It focuses on U.S. patents and points to resources for other countries.
Understand design vs. utility patents
Check for both utility patents, which protect how a product works, and design patents, which protect how it looks. Many products can be covered by one, the other, or both.
The USPTO explains the difference in plain terms: a utility patent protects the way an article is used and works, while a design patent protects the way an article looks. It also notes that an article can have both, if the invention lies in its function and its ornamental appearance.
Here's how that plays out with real products:
A kitchen gadget with a clever hinge might be covered by a utility patent on the mechanism.
A water bottle with a distinctive shape might be covered by a design patent on its appearance.
A phone stand with both a new folding mechanism and a signature look could be covered by both.
There's also a third type, plant patents, which apply to certain new plant varieties. They're rarely relevant to typical dropshipping products, so this guide focuses on the first two.
It helps to know why this matters to a retailer who never makes anything. Patent rights generally aren't limited to manufacturers. In U.S. design patent law, for example, 35 U.S.C. § 289 reaches anyone who sells or exposes for sale an article to which a patented design, or a colorable imitation of it, has been applied. So the fact that your supplier ships the product doesn't automatically keep you out of a dispute.
That doesn't mean finding a patent automatically stops you from selling. In some cases, genuine products that were first sold with the patent holder's authorization may be lawfully resold under the patent exhaustion doctrine, which the U.S. Supreme Court addressed in Impression Products v. Lexmark.
Whether it applies depends on the product's sourcing and the circumstances of the original sale. Selling an unauthorized copy is a different situation from reselling a genuine product the patent holder sold.
Look for patent numbers and other clues
Patent numbers often appear on the product, its packaging, the manufacturer's website, or the product page. The absence of a number, though, doesn't mean there's no patent.
Start with the easiest checks, since they cost nothing:
1. Search the product name with the word "patent." A simple web search like "[product name] patent" sometimes turns up a patent number the owner has posted, or an article that mentions it.
2. Look at the product page and the brand's website. Owners sometimes list patent numbers in product descriptions, footers, or a dedicated "patents" page.
3. Check the product and packaging if you can get a sample. Owners often mark products with the word "patent" or "pat." followed by a number, although they don't always do so.
4. Read "patent pending" carefully. That phrase generally signals that an application has been filed, which isn't the same thing as a granted patent. It's still worth noting, because an application could become a patent later.
A patent attorney's walkthrough on checking whether a product is patented makes a useful point about patent marking: owners can mark products to give the public notice of a patent, but marking isn't always present. So treat what you find as a clue, not as proof either way.
Make a note of two more things while you're looking: the brand name and the legal name of the company behind it. You'll need the owner's name in the next step, and the legal name is often listed in a site's terms or privacy page.
Search the USPTO patent database
Use the USPTO's Patent Public Search to look up a patent by number or to search by keywords, inventor, or owner across U.S. patents and published patent applications. It's the official place to start. Starting November 7, 2026, the USPTO says Patent Public Search will require users to sign in with a USPTO account, so create one in advance if you don't have one.
The tool has a Basic Search and an Advanced Search. According to the USPTO's Basic Search quick reference guide, Basic Search lets you enter a patent number or published application number directly, or run simple keyword queries across patents and published applications. Advanced Search opens in its own tab and gives you more control over the query.
Here's what a first search looks like:
1.Open Patent Public Search and choose Basic Search.
2.Enter a patent number if you have one, or keywords that describe what the product does, such as "foldable phone stand hinge."
3.Open a result from the list.
4.Check four things: whether it's a utility or design patent, who the owner is, what the drawings show, and the patent's status.
A few ways to widen the search:
• Search by what the product does. Use plain keywords that describe the function, not the marketing name. Patents often use technical wording, so try several phrasings of the same idea.
• Search by the owner's name. Searching by a company's legal name may help you find related patents. Keep in mind that patent ownership can change, and not every relevant patent will necessarily appear under the same company name.
• Look for related patents. An owner may have filed related applications, such as continuations, that build a family of patents around one product. The attorney walkthrough above recommends checking for these once you find a patent.
• Use classification codes. Patents are sorted into technology categories, so once you find one relevant patent, you can search its category to find similar ones. This often turns up patents that keyword searches miss.
• Save anything close. Write down the numbers of any patents that look relevant, so you can review them in the later steps.
A quick warning about older guides online: some articles still describe retired USPTO search tools and older classification systems. If a guide sends you to a tool that no longer exists, check the date and look for a current source.
Search design patents by image with Doba AI
Design patents are about appearance, so comparing images can find matches that keyword searches miss. Shapes and surface designs are hard to describe in words, which is why text searches often fall short for them.
Doba's AI Design Patent Check, part of the AI Tool Hub, is one example of an image-based check:
1. Start the check. Use a Doba Item No., or upload an image yourself.
2. Let the system compare. It checks the image against active design patents in national patent-office databases.
3. Review the similar patents. The system returns patents that look similar to your image.
4. Compare and decide. You look at the results and decide how to use them.
A few things to keep in mind when you read the results:
• It's a screening step. The tool shows you what's similar in the records. It doesn't guarantee you won't receive a complaint, and the listing decision and responsibility stay with you.
• The similarity score isn't graded. It's a raw model value, and there's no standard for what counts as high, so look at the images side by side.
• A different photo won't change the answer. Design patents protect how a product looks, regardless of which photo you use.
• It covers design patents only. It looks at appearance, so it isn't a search of utility patents.
The check costs 2 Credits per image, and a failed check isn't charged, so you can run it again. See Doba's launch guide for how to read the results, and the pricing page for plan details.
Check patent status and international records
A patent can be granted and later lapse or expire, and patents are issued country by country, so check status and the markets you sell in before drawing conclusions.
Utility patents. According to the USPTO's Maintain your patent page, utility patents need maintenance fees at set points after issuance. If they aren't paid, the protection lapses. Utility patents generally expire 20 years from the application filing date, subject to payment of the required fees.
Design patents. Design patents have different terms. In the U.S., design patents based on applications filed on or after May 13, 2015 generally last 15 years from the grant date, according to the USPTO's patent term calculator page. Earlier design patents generally have a 14-year term. Unlike utility patents, design patents do not require maintenance fees. When reviewing a design patent, check its filing date, grant date, and current legal status rather than relying on the publication date alone.
The USPTO doesn't calculate expiration dates for patents, but it offers a downloadable Patent Term Calculator to help estimate them. For utility patent maintenance fee status, the USPTO's Maintenance Fees Storefront shows payment dates and fees for a specific patent, and it requires a USPTO.gov account. A lapsed utility patent isn't always permanently dead, so if a patent is central to your decision, recheck its status and talk to an attorney before relying on a lapse.
Other countries. A U.S. search doesn't cover products sold elsewhere, so repeat the search for each market you sell into. Search the countries your customers are in, rather than trying to cover the whole world.
For utility patents, use resources such as the European Patent Office's Espacenet and WIPO PATENTSCOPE to explore patent documents from multiple jurisdictions. Google Patents offers a convenient first look across records from many offices.
For industrial designs, use WIPO's Global Design Database to search published design registrations from participating offices. You may also need to check national or regional registers directly, since database coverage varies.
Foreign patents may be written in other languages, and machine translation can help you judge whether a result is relevant. If you only sell to U.S. customers, you can concentrate on U.S. records, but a product patented abroad may still matter if you expand.
What to do if you find a similar patent
Finding a similar patent is a reason to look closer, not a conclusion. Work through these steps before you decide whether to list.
1.Read what the patent covers. A patent protects only what it claims, so read the claims for a utility patent or the figures for a design patent. Titles and abstracts are summaries, and they can be misleading.
For a utility patent, the claims are the numbered statements near the end of the document. They define the boundaries of the protection. Reading them closely is how you tell whether your product does what the patent describes.
For a design patent, the drawings are what matter, since the USPTO describes a design patent as covering the visual ornamental characteristics of an article. Pay attention to solid and broken lines in the drawings. Solid lines generally show the claimed design, while broken lines may indicate surrounding features or boundaries that are not claimed. Check the patent's written descriptions to understand how the lines are used. Compare the figures with your product's overall look, from the angles shown.
2.Compare the whole picture. Don't stop at one similar feature. Look at how the product as a whole matches what the patent describes or shows, and note any meaningful differences. Judging whether a difference is enough is a legal question, so don't conclude on your own that you do or don't infringe.
3.Confirm the status and the markets. Check whether the patent is still in force, using the filing date, grant date, and legal status, and whether it covers the countries where you sell.
4.Ask your supplier about sourcing and authorization. Ask whether the product is genuine and was sold with the patent holder's authorization, since that's what the exhaustion question turns on. Get the answer in writing.
5.Keep notes. Record the date, the databases you searched, the terms you used, and what you found. Those notes show the care you took.
6.Get legal advice if there's real doubt. If a patent looks close to your product, ask a qualified IP attorney to review it before you list.
Keep one limit in mind throughout: a search you run yourself can find patents, but it can't prove that none exist. Keywords miss things, each country's records are separate, and new applications are published all the time, so a result only shows what's on file when you run it. For a product you plan to sell in volume, an IP attorney can run a more thorough search and give you a real opinion.
Make this a routine before you list any new product: check the clues, search the records, run an image-based check for design patents, confirm status, and save your notes. To add an image check to that routine, explore AI Design Patent Check in the Doba AI Tool Hub. For related background, the Legal & Policy Basics section of the Doba blog covers other legal topics for online sellers.
Frequently Asked Questions
Q1:Does "patent pending" mean a product is patented?
Not necessarily. The phrase generally signals that someone has filed a patent application, which isn't the same as a granted patent. It's still worth noting, since an application could be granted later and you'd want to know.
Q2:Can a product be patented in one country but not another?
Yes. Patents are issued country by country, so a product can be protected in one market and not in another. If you sell internationally, search the records for each country where you have customers.
Q3:Can I still sell a product if I find a patent on it?
It depends on what the patent covers, whether it's still in force, where you sell, and how the product was sourced. Finding a patent isn't the same as finding a problem, since genuine products first sold with the patent holder's authorization may be lawfully resold under patent exhaustion. But it's a reason to read the claims or figures closely, and to ask a qualified IP attorney if it looks close to your product.
Q4:How do I check whether a patent has expired?
For a utility patent, look at when it was filed and whether maintenance fees were paid. The USPTO's Maintenance Fees Storefront shows this information, and its Patent Term Calculator helps estimate expiration dates. For a U.S. design patent filed on or after May 13, 2015, the term is generally 15 years from the grant date, and design patents don't require maintenance fees, so a lapse for non-payment doesn't apply to them.
Q5:Does Doba's AI Design Patent Check search utility patents?
No. It covers design patents, which protect how a product looks, so it isn't a search of utility patents. It compares your image with active design patents and shows similar ones, but it doesn't guarantee you won't receive a complaint, and you decide whether to list. It uses 2 Credits per image.
