Patent search guide
Freedom-to-operate search: clearing a product in the US and Europe
By Dharmik Patel, Co-founder, PatentAssist.ai
Updated
A freedom-to-operate (FTO) search, also called a clearance search, checks whether a product you plan to launch falls within the claims of someone else's patent. It is narrower than a patentability search in one way (only in-force claims, only your countries) and much harder in another: you have to read claims the way a court would. This guide covers what is in and out of scope, how status checks work at the USPTO, the EPO and the UPC, the US law on willful infringement, and what to do with a risky patent.
Quick answer
- Question: could this product, in these countries, infringe an in-force claim?
- Scope: granted patents in force plus pending published applications, country by country. Expired and lapsed patents are out, after you check.
- Status: confirm every risky hit in the European Patent Register, national registers and USPTO Patent Center, including any UPC opt-out.
- US damages: up to three times for willful infringement (35 U.S.C. 284, Halo v. Pulse). Not having an opinion cannot be used to prove willfulness (35 U.S.C. 298).
- Outcome: a ranked list of patents, with a design-around, license, validity challenge or expiry plan for each.
What FTO covers, and what it ignores
Infringement is measured against claims, so FTO is a claims search. The description and the abstract help you find the document; only the claims decide whether it matters. In the US, whoever without authority makes, uses, offers to sell, sells or imports a patented invention during the term infringes (35 U.S.C. 271(a)), and inducing or contributing to someone else's infringement is covered too (271(b) and (c)). In Europe, the extent of protection is set by the claims, with the description and drawings used to interpret them (Art. 69 EPC), and the Protocol on its interpretation tells courts to take account of equivalents.
| Document | FTO scope | Why |
|---|---|---|
| Granted patent, in force, in a country where you make, use, sell or import | In scope | The core of the search. Only its claims matter. |
| Published application still pending | In scope, as a watch item | Claims can still change and be granted. Published applications also give provisional rights: a reasonable royalty in the US if you had actual notice and the granted claims are substantially identical (35 U.S.C. 154(d)); compensation in EPC states (Art. 67 EPC). |
| European patent in the 9-month opposition period | In scope | It is in force. An opposition may narrow or revoke it later (Art. 99 EPC). |
| Expired, lapsed for non-payment, revoked or abandoned | Out (after checking) | No longer enforceable. Confirm the status in the register; a US patent lapses only after the 6-month grace period for the maintenance fee (35 U.S.C. 41(b)(2)). |
| Patent granted only in countries where you do not operate | Out | Patents are territorial. Check where you manufacture and ship, not only where you sell. |
| Applications filed in the last 18 months | Cannot be searched | Not yet published (35 U.S.C. 122(b), Art. 93 EPC). Repeat the search before launch. |
Two points are easy to miss. First, your own patent does not clear you. If an earlier patent claims "a fastener with a clip" and you patent "a fastener with a clip made of shape-memory alloy", your product can be new and still infringe the earlier claim. Second, expired patents are useful: whatever an expired patent disclosed is free to use, so an old patent that reads on your product is the best evidence you can have that the design is safe, and the starting point of a design-around.
Jurisdiction by jurisdiction
United States
A US utility patent runs from grant to 20 years from the earliest US non-provisional filing date it claims (35 U.S.C. 154(a)(2)), adjusted for USPTO delays and, for some products, extended for regulatory review. It stays in force only if maintenance fees are paid at 3.5, 7.5 and 11.5 years after grant; if one is missed, the patent expires at the end of a 6-month grace period (35 U.S.C. 41(b)). Check the actual expiry date for each risky patent rather than estimating it from the filing date.
Read the prosecution history in Patent Center as well as the claims. Arguments and amendments the applicant made to get around prior art often narrow what the claims can cover.
European patents: classic, unitary and the UPC
A European patent is granted once by the EPO, then takes effect as national patents in each state where it is validated, with infringement dealt with by national law (Art. 64 EPC). Its term is 20 years from filing (Art. 63). Since 1 June 2023 the proprietor can instead ask for unitary effect, which gives one patent across the participating EU states; see the Unitary Patent guide for the 18 states covered.
For FTO this means three checks per European family. Is it validated or unitary in your countries? Is it in force there, with renewal fees paid? And which court can hear an action? The Unified Patent Court has exclusive competence for infringement actions and revocation actions on European patents in participating states (UPCA Art. 32), so one action can reach many countries. During the transitional period, which runs until 31 May 2030, actions on classic European patents can still go to national courts, and proprietors can opt a patent out of the UPC (Art. 83). A patent granted in the last 9 months can still be opposed at the EPO (Art. 99), which is often the cheapest way to deal with it; see the invalidity search guide.
National patents and utility models
Do not stop at EP. National patents filed directly at the DPMA, the UK IPO or INPI are not in the European Patent Register, and Germany also has the utility model, an unexamined right registered quickly (see the German patent guide). The UK is outside the Unitary Patent and the UPC, so UK risk always runs through UK national or validated European patents and the UK courts. In India, the rights a patent confers are set out in section 48 of the Patents Act.
Legal status checks
Search databases give you a status estimate. Before you rely on a patent being dead, or alive, confirm it at the source. Family data helps you find every member: the EPO groups documents into DOCDB simple families and INPADOC extended families, and a single invention may have live members in some countries and lapsed ones in others.
| Source | What it tells you |
|---|---|
| European Patent Register | EP applications and patents: procedural status, oppositions, unitary effect requested or registered, UPC opt-out, correspondence. Links to national registers after grant (Federated Register). |
| National registers (for example DPMAregister, UK IPO Ipsum) | Whether a validated European patent or a national patent is in force in that country, renewal fees paid, and national utility models. |
| USPTO Patent Center | Application status and the full file history, including amendments and arguments that shape claim scope. |
| USPTO Maintenance Fees Storefront | Whether the 3.5, 7.5 and 11.5-year maintenance fees were paid. A USPTO.gov account is needed to look up records. |
| USPTO Assignment Center | Recorded ownership changes, to know who would actually sue or license. |
The European Patent Register also shows whether unitary effect was registered and whether a patent has been opted out of the UPC, and its Register Alert service will email you when a watched file changes. For the UK, use Ipsum.
Opinions and willful infringement in the US
US courts may increase damages up to three times the amount found (35 U.S.C. 284). In Halo Electronics v. Pulse Electronics, decided June 13, 2016, the Supreme Court threw out the Federal Circuit's two-part Seagate test as "unduly rigid". Enhanced damages are for "egregious cases typified by willful misconduct"; subjective willfulness, intentional or knowing, can be enough without objective recklessness; culpability is measured against what the infringer knew at the time; the standard of proof is a preponderance of the evidence; and the decision is reviewed for abuse of discretion.
The counterweight is 35 U.S.C. 298: failing to obtain advice of counsel, or failing to show it to the court, may not be used to prove willful infringement or intent to induce. So an opinion is not mandatory. In practice, once you know about a specific patent that looks close, a written opinion from a US patent attorney, analyzing the claims against the product and the prosecution history, is the usual way to document that you formed a good-faith view before launch. A search report alone is not an opinion.
The UPC works differently. Its damages aim to put the injured party where it would have been without the infringement and "shall not be punitive" (UPCA Art. 68). The bigger European risk is an injunction, which at the UPC can cover every participating state where the patent is in force.
Steps and deliverables
- Freeze the scope. Describe the product as it will actually ship, broken into features and components, and list the countries of manufacture, sale and import.
- Search by feature. Classification codes and keywords for each feature, plus assignee searches on the known competitors and suppliers. Limit to documents that may be in force: in practice, families with an earliest filing date within the last 20 years or so, plus extensions.
- Filter by status. Drop expired and lapsed families only after checking the register.
- Read claims. Independent claims first. A claim is infringed literally only if the product has every element; one missing element clears that claim, unless an equivalent is present.
- Chart the close ones. For each risky patent, an element-by-element chart against the product, with the prosecution history noted.
- Decide. Design around, take a license, challenge validity, or wait for expiry, and record the reasoning.
| Deliverable | Contents |
|---|---|
| Scope statement | The product or process as it will ship, the features searched, the countries, and the date the search was run. |
| Search record | Databases, classification codes, keyword strings, assignee searches and the number of documents reviewed. |
| Hit list with status | Every family reviewed, its status in each relevant country, expiry date and owner. |
| Claim charts | For the patents that come closest: each independent claim split into elements and compared with the product. |
| Risk ranking and options | High, medium, low, with the reason, and a recommended action for each high-risk patent. |
| Opinion (optional) | A lawyer's written non-infringement or invalidity opinion on specific patents, where the risk justifies it. |
Design-around: a worked example
Illustrative only; the patent is hypothetical. A company plans to sell an e-bike battery mount in Germany, France and the US. The FTO search turns up a European patent with unitary effect and a US counterpart. Claim 1 reads, in short: a mount comprising (a) a rail fixed to the frame, (b) a battery housing that slides on the rail, and (c) a spring-loaded latch that engages a notch in the rail.
The product has (a) and (b). Instead of a spring latch it uses a magnetic catch. Is that an equivalent of (c)? The file history helps: during US prosecution the applicant distinguished a cited reference by arguing that its claim needed a mechanical, spring-biased engagement. That argument makes it hard to stretch (c) to cover a magnet. The team still checks the dependent claims and the pending continuation, which might claim "a latch" more broadly, and sets an alert on it.
The decision: ship with the magnetic catch, get a written US opinion because the patent is known to the company, file their own application on the magnetic design, and watch the continuation. If the European patent were within its 9-month opposition window, opposing it at the EPO would also be on the table.
Where PatentAssist fits in an FTO search
PatentAssist's patent search helps with the finding: describe a product feature in plain language, or search by CPC or IPC class, applicant or keyword, across USPTO, EPO and IP India records, then read the claims and family members of each hit. That is a fast way to build the first candidate list.
It is not an FTO tool on its own. It does not confirm the legal status of US or European patents, renewal payments or UPC opt-outs, and it does not give infringement opinions. Use the official registers above for status, and a patent attorney for the analysis of any patent that comes close.
More patent guides
- Patent drawing requirements: USPTO, EPO and India
37 CFR 1.84, the EPO rules that replaced Rule 46 EPC, and Indian rule 15, compared side by side.
- How to write patent claims: USPTO, EPO and India
Claim structure and worked examples, then the claim rules and fees at the USPTO, the EPO and the Indian Patent Office, side by side.
- Types of patent searches, and which one you need
Patentability, freedom-to-operate, invalidity and landscape searches compared by purpose, timing, scope and deliverable.
- Patentability search: how to check novelty before you file
What counts as prior art under 35 U.S.C. 102 and Art. 54 EPC, the grace period gap, search steps and how to read results.
- Invalidity search: prior art to challenge a patent
IPR, PGR, EPO opposition and UPC revocation deadlines, prior art dates, standards documents and claim charts.
- Patent landscape analysis, step by step
Building a CPC and keyword dataset, cleaning families and names, the metrics that matter and the 18-month publication lag.
- Google Patents search guide
Search operators and fields, Boolean and proximity syntax, non-patent literature, and where Google Patents falls short of the official databases.
- The Cooperative Patent Classification (CPC), explained
How CPC symbols are built, CPC against IPC, the Y section, how to find the right class and how to search it in each database.
- Patent search Boolean operators and search strings
Boolean, proximity and truncation syntax compared across Patent Public Search, Espacenet, Google Patents and The Lens, with semantic search for contrast.
- The PCT application: timeline, fees and national phase
The international phase month by month, receiving Office and ISA fees in CHF, USD and EUR, national phase deadlines by office, and a deadline calculator.
- How much does a patent cost?
USPTO fees by entity size from filing to the last maintenance fee, what drives professional fees, EPO fees, and an estimator.
- How long does a patent last?
US utility and design terms, patent term adjustment and extension, terminal disclaimers, maintenance fee deadlines, Europe and India, with an expiry estimator.
- Can AI write a patent application?
What AI drafting does well and badly, the USPTO and EPO positions on AI tools, AI inventorship after 2025, and confidentiality.
Freedom-to-operate search: frequently asked questions
What is a freedom-to-operate search?
A search for in-force patents, and pending applications, whose claims could cover a specific product or process in the countries where you plan to make, use, sell or import it. It ends with a list of risky patents and options for each: design around, license, challenge validity or wait for expiry.
How is FTO different from a patentability search?
A patentability search asks whether you can get a patent and looks at all prior art, of any age and any status. An FTO search asks whether you can sell without infringing, and looks only at the claims of patents that are, or may become, in force in your markets. Owning a patent does not give you freedom to operate: a broader earlier patent can still cover your product.
Do I need an FTO opinion to avoid willful infringement in the US?
No law requires one. Under 35 U.S.C. 298, not obtaining advice of counsel, or not presenting it, may not be used to prove willful infringement. But after Halo v. Pulse (2016), courts can enhance damages up to three times for egregious, willful conduct based on what the infringer knew at the time, proved by a preponderance of the evidence. A considered written opinion on a patent you know about is evidence that you acted in good faith.
Does a European patent cover all of Europe?
No. After grant a classic European patent is a bundle of national patents in the states where it was validated (Art. 64 EPC). A European patent with unitary effect covers the participating EU states that had ratified the UPC Agreement when unitary effect was registered. Spain, Poland and Ireland, and non-EU states such as the UK and Switzerland, are outside it. Check each country you operate in.
How long does a freedom-to-operate search stay valid?
Only as of the date it was run. New applications publish every week, pending claims get amended, and patents lapse or get revoked. Repeat the search before launch, set alerts on the high-risk families (the European Patent Register offers Register Alert), and update it when the product design changes.
Should I check for UPC opt-outs?
Yes. A classic European patent that has not been opted out can be enforced in a single action at the Unified Patent Court for all participating states where it is in force, during the transitional period that runs until 31 May 2030. An opted-out patent must be enforced country by country in national courts. The European Patent Register shows whether a patent has been opted out.
Sources: 35 U.S.C. 41, 122, 154, 271, 284 and 298; Halo Electronics v. Pulse Electronics, 579 U.S. 93 (2016); EPC Articles 63, 64, 67, 69, 93 and 99 and the Protocol on the Interpretation of Article 69; Agreement on a Unified Patent Court, Articles 32, 33, 68 and 83; EPO, European Patent Register; USPTO Patent Center; USPTO, maintain your patent. This guide is general information, not legal advice. Have a patent attorney review any patent you think may cover your product.