Patentability search: how to check novelty before you file

What a patentability search is, and what it is not

A patentability search looks for anything published before your filing date that discloses your invention, or comes close enough that the step to it would be obvious. The question is about your claims: can you get them granted? It does not matter whether the documents you find are 5 or 50 years old, granted or abandoned, in force or expired. Prior art is prior art.

That is the main difference from a freedom-to-operate search, which asks whether a product infringes someone else's in-force claims, and from an invalidity search, which hunts for prior art against a patent that has already been granted. The types of patent searches guide compares all of them in one table.

No US rule makes you search before filing. What you must do under 37 CFR 1.56 is disclose to the USPTO information you know to be material to patentability, so whatever your search turns up and you judge material goes into an information disclosure statement. That is a reason to keep good records of the search, not a reason to avoid one.

When to run it

• Before any public disclosure. A talk, a demo, a crowdfunding page or a paper can become prior art against you in Europe the day it goes public. The search and the filing decision should come first.
• Before drafting a US provisional. A provisional secures a date only for what it describes. If the search shows the core idea is known, you want the provisional to describe the narrower features you will actually claim. See how to file a provisional patent application.
• Before an EP or PCT first filing. The EPO search fee is €1,595 from 1 April 2026 (Rules relating to Fees, Art. 2(1) item 2), and the extended European search report usually comes months after filing. Your own search first lets the application go in with claims that already avoid the obvious hits. See how to file a European patent application.
• Before investing in development. If the core feature is old, it is better to learn that before the prototype budget is spent.

For scale, the official search you pay for when you file a US utility application is $770 at the standard rate, $308 for a small entity and $154 for a micro entity (37 CFR 1.16(k), fees effective January 19, 2025). That search is done by the examiner after filing. It does not replace your own: by then the specification is fixed and you cannot add new matter.

What counts as prior art: US and Europe compared

Both systems define prior art broadly: anything made public, anywhere, in any form, before your date. They differ on earlier-filed applications and on grace periods, and the grace period is where most applicants get caught. The statutory text, with commentary, is in our annotated 35 U.S.C. 102 reference.

Sources: 35 U.S.C. 102; MPEP 2152.02; Articles 54, 55, 56 and 89 EPC.

The grace period trap

In the US, a disclosure you made one year or less before the effective filing date is not prior art against you (MPEP 2153.01(a)). The same goes for a disclosure by someone who got the idea from you. Europe is stricter. The EPO's Guidelines say there are only two cases in which a prior disclosure is ignored: evident abuse, such as a disclosure against your wishes, and display at an officially recognized international exhibition. Both must fall within 6 months before filing. A conference talk or a product launch is neither.

So if you have already disclosed, a US filing may still be possible within 12 months, but a European patent for the same subject matter is usually lost under the absolute novelty rule in Article 54 EPC. India sits in between: section 31 of the Patents Act gives 12 months for display at a notified exhibition or a paper read before a learned society, and section 29 covers publication without the inventor's consent. Your patentability search should include your own earlier publications, posts and demos, with dates.

Scope: patents and non-patent literature

Search patent documents from every major office, not only the ones where you plan to file. A Chinese utility model or a Korean application is prior art in the US and at the EPO. Espacenet holds more than 150 million documents with machine translation; the USPTO's Patent Public Search has full-text US documents; WIPO's PATENTSCOPE covers PCT applications and many national collections.

Then search non-patent literature (NPL). Both offices treat online material as prior art. The MPEP says an electronic publication, including an online database, forum, video or social media post, is a printed publication if it was accessible to people concerned with the art (MPEP 2128). The EPO treats internet disclosures as state of the art from the date they were posted, and password protection or a paywall does not change that (Guidelines G-IV 7.5.1). Final standards are prior art too, and standard preparatory documents count if they were public without a confidentiality bar (G-IV 7.6).

Where to look depends on the field: journal and conference databases, university thesis repositories, product manuals, app store listings, code repositories, archived web pages, and standards bodies such as ETSI, IEEE or 3GPP. In software and consumer electronics the closest art is often a product page or a manual, not a patent.

How to run a patentability search, step by step

1. Write a one-paragraph summary and split it into features. Number them F1, F2, F3. The feature you think is new should be its own line. This list becomes the spine of the search and of the report.
2. Build the vocabulary. For each feature, list synonyms, broader and narrower terms, and the words a patent attorney would use ("fastening means" rather than "clip"). Patents are written to be broad, so plain product words miss them.
3. Find the classification codes. The Cooperative Patent Classification (CPC), run jointly by the EPO and the USPTO, is the most detailed scheme. Take the CPC codes from the two or three most relevant documents you find early on, and check their definitions. Classification searching finds documents that use words you did not think of.
4. Run three kinds of query. A plain-language or semantic search to find the first good hits fast; Boolean keyword queries with proximity operators for precision; and classification queries combined with a few keywords for recall.
5. Chase citations. For the best hits, read the documents they cite (backward) and the documents that cite them (forward), and the examiner citations in their search reports.
6. Search NPL. Use the vocabulary list on scholarly databases, standards repositories and the open web. Record the publication date and how you know it.
7. Screen and map. Read the claims and the detailed description of the top 10 to 20 documents, not just the abstract, and mark which features each one discloses.
8. Write it up. The search strategy (databases, queries, codes, date run), the closest documents with pinpoint citations, the feature matrix and a conclusion on claim scope.

Worked example: a smart pill dispenser

This example is illustrative. The documents D1 to D3 are hypothetical and stand for the kind of results a search returns. The invention is a home pill dispenser that weighs each compartment and can tell whether a patient took a dose out and then put it back.

No single document has F1 to F3 together, so a claim to F1 + F2 + F3 would be novel. It would not survive an obviousness or inventive step attack, though: D2 has the carousel and the weight sensors, D1 adds the caregiver alert, and both are in the same field. An examiner would cite them as Y documents. F4 appears nowhere, and it has a technical effect (it catches the "took it out, put it back" case that a lid sensor misses). The realistic claim is F1 + F2 + F4, with F3 in a dependent claim, and the specification should explain the weight-change logic of F4 in detail, with alternatives, because that is where the patent will be won or lost.

How to read the results

The EPO's citation categories are a good way to sort your own results, and you will see the same letters in the search report after filing (Guidelines B-X 9.2).

An X document against your main idea is not the end. It usually means the claim has to move to the feature that made the invention worth building. Ask three questions of each close document: what does it not disclose, would a skilled person have a reason to add the missing feature, and does the missing feature produce a technical effect you can describe? If the answer to the last one is no, the application will struggle at the EPO, where inventive step is assessed against the technical problem solved. The claim side of this is covered in how to write patent claims.

One caution on dates. Applications are normally published 18 months after their earliest priority date, so anything filed in the last 18 months is invisible to every search. Those filings can still be prior art against you under 102(a)(2) or Art. 54(3). No search can rule them out.

DIY or professional, and what it costs

There is no official price for a private patentability search, and we have not found a primary source that publishes reliable market rates, so we do not quote one. Price depends on how crowded the field is, whether NPL is included, how many documents are analyzed in depth and whether you get a written opinion. Ask for a fixed quote that states the databases, the NPL sources and the number of documents reviewed.

• Do it yourself to screen ideas, to find the obvious knock-out document, and to give your attorney a head start. Free tools and an AI search get you surprisingly far in an hour.
• Use a professional searcher when the filing budget is significant, the field is crowded (medical devices, batteries, wireless), investors will rely on the result, or the art is mostly in non-English documents or NPL.
• Get an attorney's opinion on the results when you need a decision on claim scope rather than a list of documents.

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.

• Freedom-to-operate search in the US and Europe

  In-force claims only, legal status checks at the USPTO, EPO and UPC, FTO opinions after Halo, and design-arounds.

• 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.

All guides, by patent office