Filing a patent for an invention is a process aimed at protecting a technical innovation. It grants the patent holder an exclusive monopoly to exploit their invention, preventing third parties from reproducing, using, or selling it without authorisation.
Filing a patent for an invention requires thorough preparation and deep understanding. In this article, we explain what a patent is, the procedure to follow, and the essential elements involved.
We will also cover the European patent, which allows for extended protection at the European level.
What does filing a patent for an invention mean and what is it for?
Filing a patent for an invention is a legal process through which the holder of an invention obtains an exclusive exploitation right, for a fixed period, over a new, inventive, and industrially applicable technical solution. This protection is granted by the State in exchange for the public disclosure of the invention, thereby balancing the inventor’s interests with the technical progress of society.
Patent registration is not merely an administrative formality: it is a strategic tool to protect intangible assets, block competitors, and increase the commercial value of an innovation. Companies investing in R&D or seeking international expansion should consider patents as a core element of their innovation protection strategy.
Legal definition of a patent for an invention
A patent is an intellectual property title that grants its holder the exclusive right to commercially exploit an invention within a specified territory for a limited period, typically up to 20 years from the filing date. The invention must be a product or process that provides a novel and non-obvious technical solution to a specific problem.
This exclusive right prevents others from manufacturing, using, offering for sale, selling, or importing the patented invention without the patent holder’s authorisation, and unauthorised use may constitute an infringement of industrial property rights.
What rights does it grant to the holder?
Filing a patent for an invention grants the holder the following fundamental rights:
- Right of exclusivity: to prevent third parties from using the invention without consent.
- Right to license or assign: to authorise third parties through contractual licences or to sell the patent as an intangible asset.
- Right to take action against infringers: to file civil or criminal claims for unauthorised use.
- Right to include the patent as a business asset, which can enhance company value in investment, merger, or internationalisation processes.
In addition, a patent can be a source of income through licensing to third parties, technology franchises, or transfer agreements.
Difference between a patent, utility model, and trade secret
It is crucial not to confuse invention patents with other forms of protection:
| Protection | Requirements | Duration | Advantages |
|---|---|---|---|
| Invention patent | Novelty, inventive step, industrial application | 20 years | Strongest protection and highest legal prestige |
| Utility model | Novelty, lower degree of inventiveness | 10 years | Faster and more cost-effective |
| Trade secret | Not registered, protected through confidentiality | Indefinite (if kept secret) | No registration costs, but more vulnerable |
For example: a new pharmaceutical molecule could be patented; an improvement in the design of a hand tool could qualify as a utility model; while a beverage formula, if kept secret, would be protected as a trade secret.
Concrete examples of patents in different sectors
- Technology: a new type of biometric sensor with higher precision for mobile devices.
- Chemistry: an improved process for synthesising biodegradable materials.
- Software: algorithms that solve specific technical problems, such as data compression or image recognition (in certain countries and under certain conditions).
- Medicine: innovative medical devices, such as an inhaler with an intelligent dosing system.
These examples illustrate that patents can be found across all productive sectors, from digital startups to major pharmaceutical companies or engineering firms.
Legal requirements: when is an invention considered patentable?
For an invention to be legally patentable, it must meet the requirements established under both national and international legislation. Compliance with these criteria is assessed by the Patent and Trademark office (of each country) and, at the European level, by the European Patent Office (EPO).
Novelty: what does it mean for an invention to be “new”?
An invention is considered new if it has not been publicly disclosed anywhere in the world before the filing date of the application or the priority date. Novelty must be absolute, which includes disclosures in scientific journals, prior patents, exhibitions, or even by the inventor themselves if made public without prior protection.
🔎 Practical tip: Always conduct a prior art search in databases such as Espacenet, Patentscope, or the OEPM database.
Inventive step: how is the technical leap assessed?
An invention must involve an inventive step—meaning it must not be obvious to a person skilled in the art in light of the existing state of the art. This requirement is crucial to prevent the registration of mere obvious improvements or trivial combinations.
Examiners apply the “problem–solution” approach to assess whether the invention truly delivers a non-obvious technical advance. For example, if a new medical device combines two already known technologies but does so in a way that solves a clinical problem that no one had previously resolved, it will be considered to involve an inventive step.
Industrial application: are all ideas patentable?
To be patentable, the invention must be capable of industrial application—in other words, it can be manufactured or used in any type of industry or economic activity. This requirement excludes abstract ideas, scientific theories, or purely intellectual methods that cannot be materialised.
For instance, a theory about quantum behaviour without a concrete application is not patentable, but a device that uses quantum principles to improve cryptography could be.
Exclusions from patentability
Even if an invention meets the three core requirements above, certain subject matters are expressly excluded from patent protection under patent act and the European patent convention, such as:
- Discoveries, scientific theories, and mathematical methods.
- Methods of surgical or therapeutic treatment of the human or animal body.
- Computer programs as such, without any additional technical effect.
- Inventions contrary to public policy or morality, such as human cloning processes.
- Plant varieties or animal breeds, except for modified microorganisms.
Knowing these limitations allows for a more strategic drafting of a patent application, avoiding unnecessary refusals.
When is it advisable to patent an innovation? Practical recommendations
Deciding when to file a patent application is just as strategic as the innovation itself. Filing too early can jeopardise novelty if the invention is not yet ready, while filing too late may leave it exposed. The right timing depends on the type of innovation, the sector, and the patent holder’s objectives.
Patent before or after commercialisation?
The answer is clear: always before any public disclosure. Once an invention is presented to the market—at trade fairs, on websites, in meetings with investors, or on social media—without prior protection, the novelty requirement is automatically lost, which may cause the application to be refused.
💡 Legal tip: Before seeking funding, signing distribution agreements, or presenting the innovation publicly, protect it through a formal patent application or, at the very least, by using Non-Disclosure Agreements (NDAs).
How to protect during the prototype phase
During the development or proof-of-concept stage, even without a final product, it is possible to file a provisional patent or a priority national application in the national member state. This grants a priority date for 12 months, during which you can extend protection internationally. You can also safeguard technical information through:
- Non-Disclosure Agreements (NDAs)
- Access control protocols for technical documentation
- Notarial documentation of the development process
Startups, individual inventors, and established companies
- Startups and individual inventors should view patents not only as legal protection but also as an asset that increases company valuation, facilitates investor attraction, and opens monetisation channels (licensing, collaboration agreements, technology grants).
- Established companies often integrate invention protection into a global R&D strategy, complementing patents with additional measures such as trademark protection, trade secrets, and other intellectual property tools.
Real cases: when it paid off… and when it didn’t
- ✅ Success: A biotechnology company patented a cell culture process during the experimental stage. After obtaining the patent, it signed multi-million licensing agreements with international laboratories.
- ❌ Mistake: An inventor showcased their innovation at a technology fair without having applied for protection. When attempting to register the patent months later, it was rejected for lack of novelty, as it had already been publicly disclosed.
⚠️ Patenting at the right time can make the difference between commercial success and losing rights altogether.
How to file an invention patent | step-by-step procedure
Filing a patent for an invention involves following a structured legal and technical process, where each stage is crucial to ensuring the strength of the protection. Below, we detail the step-by-step procedure:
1. Prior art search (patent search)
Before drafting and filing the application, it is essential to conduct a search in patent databases such as Espacenet, WIPO, or the OEPM to verify that the invention has not been previously disclosed. This stage allows you to:
- Assess the viability of the patent.
- Fine-tune the claims.
- Avoid duplication and save costs.
2. Technical and legal drafting of the specification
The specification — or memoria descriptiva — is the heart of the patent. It must include:
- A detailed description of the invention.
- Clear claims that define the scope of protection.
- Drawings or diagrams, if required.
It is essential that this drafting be carried out by both legal and technical experts, as the effectiveness of the protection and its defence against third parties depend on it.
3. Filing the application (EPO, WIPO) for a patent on an invention
The application may be filed with:
- The national trademark and patent office depending on the country
- The EPO (European Patent Office) to obtain a European Patent.
- The WIPO (World Intellectual Property Organization) through the PCT system for international protection.
A sound strategy may involve first filing at the national level and, within the following 12 months, extending protection internationally while retaining the priority date.
4. Formal examination and substantive examination
After filing, the following examinations take place:
- Formal examination: checks that the documentation is complete and correctly formatted.
- Substantive examination: evaluates whether the invention meets the requirements of novelty, inventive step, and industrial application.
This process may take between 12 and 24 months, depending on the country and the filing route chosen.
5. Grant of the patent
Once the examination has been successfully completed and, where applicable, any oppositions resolved, the patent is granted. At this stage, the holder must:
- Pay the grant fees.
- Publish the final text.
- Pay annual fees to maintain the validity of the right.
6. Publication in the Official Gazette and opposition
Once granted, the patent is published in the official gazette, depending of the country. From that point onwards, third parties may file oppositions or observations. Publication also has a deterrent effect, as it publicly informs of the existence of the invention and its potential ownership.
Language of the procedure and required translations
Official language of the patent office
In patent procedures before a national patent office, the official language of that office will apply. All documents, including the specification (description, claims, and drawings), must be submitted in that official language. If the application is initially drafted in another language (for example, English), a certified or legally valid translation into the official language will be required.
Translations required in European or International patents
In proceedings before the European Patent Office (EPO), applications may be filed in English, French, or German. However, upon entering the national validation phase, many countries require a partial or complete translation into their official languages (for example, Italian, Dutch, or others).
For PCT (international) applications, the language chosen in the international phase must be accepted by the Receiving Office. Nevertheless, translations will be required in the national phase for each designated country according to its language requirements.
How long does a patent remain valid?
One of the most common questions when filing a patent for an invention is how long the legal protection lasts. The duration of a patent is regulated by law and depends on maintaining the right over time.
General duration: 20 years from the filing date
In most jurisdictions worldwide, including under international agreements, the duration of a patent is 20 years counted from the filing date of the application. During this period, the patent holder can prevent third parties from manufacturing, using, or marketing the invention without their consent. This time limit is designed to balance incentivising innovation with ensuring that technical knowledge enters the public domain after a reasonable period.
Requirements to maintain the patent: payment of annual fees
Although the maximum duration is 20 years, the right is not maintained automatically. It is mandatory to pay annual maintenance fees to the relevant patent office (national, regional, or international).
Each annual fee must be paid within a specific deadline, and the amount generally increases progressively over the years. Failure to pay results in the automatic lapse of the patent, meaning the complete loss of the right.
📌 Practical tip: Plan the payment of annual fees in advance and link them to a legal calendar or CRM reminder system to avoid oversights that could cost you the asset.
Possibility of extension in exceptional cases: pharmaceutical products
There are specific situations where protection may be extended beyond 20 years. This is particularly the case for pharmaceutical and plant protection products, where lengthy marketing authorisation procedures can reduce the effective exploitation period. In such cases, the patent holder may apply for a Supplementary Protection Certificate (SPC), which can extend the patent duration by up to 5 additional years, but only for the authorised product. This measure aims to compensate for the time lost between the granting of the patent and the marketing authorisation.
Specific cases and exceptions to patentability
While filing a patent for an invention is a solid legal way to protect technological developments, not all creations or discoveries can be protected through a patent. National, European, and international legislation set clear limits to prevent abuses or conflicts with higher interests such as public health or morality.
Inventions contrary to public policy or morality
Excluded from patentability are inventions whose exploitation could be contrary to public order or good morals. This includes, among other examples:
- Human cloning processes
- Methods for genetic modification of the germline
- Use of human embryos for industrial or commercial purposes
This clause acts as an ethical safeguard against technological advances that, while technically feasible, are not acceptable from a legal or social perspective.
Surgical and diagnostic methods applied to the human or animal body
The European Patent Convention expressly excludes from patentability surgical, therapeutic, or diagnostic methods applied directly to the human or animal body. This does not mean that all medical innovation is excluded from protection. The following can be patented:
- Medical devices (e.g., robotic scalpels, portable scanners)
- New substances or compounds (medicines)
- Procedures applied in vitro or outside the body
🔍 Distinction: the medical method as an act is not patentable, but the device or product that enables it can be.
Plants and animal breeds (except modified microorganisms)
Also not patentable are:
- Plant varieties or animal breeds as such
- Essentially biological processes for obtaining plants or animals (natural crossing, selection)
However, the following can be patented:
- Genetically modified microorganisms
- Processes that are not essentially biological
- Plants modified through genetic engineering that do not constitute a specific plant variety already protected under the sui generis system of Community law (CPVR)
🌱 Practical example: a specific tomato variety obtained through conventional crossing cannot be patented, but a modified gene that increases its resistance to pests can be.
What is the European Patent? Advantages and procedure
The European Patent is a mechanism that allows the applicant to request protection for an invention in several European countries through a single centralized application before the European Patent Office (EPO). It is not a “Community” patent, but rather a common procedure that results in national patents valid in each designated country.
This route is especially useful for inventors, companies, and startups that wish to protect their technology in several Member States of the European Patent Convention (EPC), reducing the initial administrative complexity.
Unified procedure before the European Patent Office (EPO)
The process before the EPO follows a rigorous but centralized technical procedure. It includes:
- Filing of the application (in English, French, or German).
- Formal and substantive examination: review of compliance with patentability requirements (novelty, inventive step, industrial applicability).
- Publication of the application 18 months from the priority date.
- Granting of the European patent, if the examination is passed.
The advantage is that a single application replaces multiple individual filings, which simplifies the first steps of international registration.
Validation country by country
Once the European patent is granted, it does not have automatic effect in all countries. It is necessary to carry out a national validation in each designated State, which may include submitting translations, paying national fees, and appointing local representatives in some countries. Each validated patent is then governed by national legislation, so maintenance (annuities), licensing, or litigation are handled country by country.
Differences with the national application
| Aspect | National application (OEPM) | European application (EPO) |
|---|---|---|
| Territorial scope | Only national | Up to 39 EPC countries |
| Language | Official | English, French, or German |
| Examination | Formal and substantive | Formal and more exhaustive substantive examination |
| Costs | Lower | Higher (but with broader coverage) |
| Translations | Not required | Required for national validations |
In the event of litigation, the management of the patent (such as infringement actions or revocation) is carried out at the national level or before the Court of Justice of the European Union (CJEU) in certain cases. See our detailed guide on how to access the CJEU.
European Unitary Patent (EUP): the major novelty in EU-wide protection
Since 1 June 2023, the European Union has taken a key step towards unified protection of inventions with the entry into force of the European Unitary Patent (EUP). Unlike the traditional European patent, the EUP produces uniform legal effects in all participating Member States, without the need for country-by-country validation.
Implemented through the Agreement on a Unified Patent Court (UPC), it allows patent holders to obtain protection in 17 European countries without having to validate their patent individually in each one. In the event of a patent infringement, holders can turn to the Unified Patent Court (UPC) for dispute resolution.
Entry into force and participating countries
The EUP came into force on 1 June 2023, together with the Unified Patent Court (UPC). Currently, 17 EU Member States participate, including Germany, France, Italy, the Netherlands, Belgium, Austria, Sweden, Denmark, Finland, Portugal, Slovenia, etc.
💡 Important: Spain, Poland, and Croatia are not currently participating in the EUP. In these countries, the national route or the classic validation of the European patent must still be used.
Differences from the traditional European patent
| Aspect | Traditional European Patent | European Unitary Patent (EUP) |
|---|---|---|
| Validation in countries | Yes, country-by-country | No, automatic unitary effect |
| Translations | Required in each country | Only one additional translation |
| Annual fee management | One per country | Single centralised annual fee |
| Jurisdiction in litigation | National courts | Unified Patent Court |
| Territorial effect | Fragmented | Single, in all participating countries |
When to choose an EUP and when not to?
It is advisable to opt for a European Unitary Patent when:
- Protection is desired in more than 3–4 participating countries.
- The aim is to simplify management and reduce maintenance costs.
- Speed and legal uniformity are prioritised.
- Litigation is preferred in a single forum (UPC) with pan-European effect.
It is not advisable to opt for the EUP if:
- Protection is sought in countries outside the EUP system (such as Spain or the United Kingdom).
- Flexibility in territorial segmentation is desired (for example, licensing per country).
- One wishes to avoid pan-European legal risk in case of total invalidity.
The choice between a classic European Patent, an EUP, or a national application should be based on a tailored legal and commercial strategy. As a law firm specialised in European Union Law, Regulatory Law, and Corporate Law — and with expertise in industrial property and the protection of inventions in Europe — we help you choose the optimal route, draft your patent specification with guarantees, and protect your innovation effectively and profitably.
Real-life success stories in invention patents
Filing a patent for an invention requires more than just a brilliant idea: the quality of the application, strict compliance with legal requirements, and a well-planned protection strategy are crucial. Numerous cases before national states and European courts have clarified what is patentable and what mistakes can lead to refusal or nullification of a patent.
1. International protection of an industrial tool developed by a French SME
A small and medium-sized enterprise (SME) specialized in agricultural machinery developed an innovative coupling system. The prototype was already being marketed and had been showcased at various trade fairs in Spain and France, yet the company had not taken steps to legally protect its invention.
Challenge: The invention was at risk of being copied, especially by Italian and French competitors.
Solution:
➡️ We immediately conducted a prior art search to assess patentability.
➡️ Drafted the technical and legal specification within 10 days, including diagrams and claims, with the support of an external industrial engineer.
➡️ Filed an urgent national application with the Spanish Patent and Trademark Office (OEPM), and within 12 months, initiated an international PCT application with translations into English and French.
➡️ The company secured the national grant within 13 months and successfully proceeded with European validation.
✅ Outcome: Active international protection in 9 key countries, no oppositions, and the patent certificate was leveraged to attract private investment
2. Defending a pharmaceutical patent against a competitor’s nullity attempt
A Portuguese biotech company approached our firm after receiving a notice that threatened one of its most valuable patents. The invention concerned a combination of active pharmaceutical ingredients with a therapeutic effect.
Challenge: A national competitor in the same market segment filed for nullity, arguing that the invention was merely an obvious combination of known substances and thus lacked inventive step.
Solution:
➡️ Prepared a comprehensive technical and legal defense, demonstrating that the therapeutic effect was unpredictable, supported by unpublished clinical studies.
➡️ Responded to the administrative challenge with a robust statement of arguments, referencing EU Court of Justice and Spanish Supreme Court jurisprudence.
➡️ Included expert opinions from two independent specialists confirming the non-obviousness of the invention.
✅ Outcome: The patent was upheld and remains in force.
3. Comprehensive advisory for a tech startup on AI and patentable software
A young Belgian tech spin-off contacted us after developing an artificial intelligence algorithm capable of optimizing energy consumption in industrial environments. Although the technology was advanced, the company was unsure about protection, since many algorithms are not patentable in Europe as they are considered computer programs “as such”.
Challenge: Uncertainty regarding the patentability of software in Europe.
Solution:
➡️ Analyzed whether the algorithm addressed a specific technical problem and met the European Patent Office (EPO) standards for patentable software.
➡️ Drafted a technical-oriented specification enabling verifiable industrial application.
➡️ Filed an application with the EPO, later validating it in Germany, France, and the Netherlands.
➡️ Simultaneously registered the software as copyright with the Intellectual Property Registry to strengthen protection.
✅ Outcome: Patent accepted for processing without objections, accompanied by an EPO technical compliance statement.
Common mistakes in patent applications that lead to rejection
Many applicants make errors that can undermine years of work, technological development, and financial investment. The quality of the application, strict adherence to legal requirements, and a well-planned protection strategy are critical. Some of the most frequent mistakes when filing an invention patent include:
- Describing the invention ambiguously or incompletely (insufficient disclosure).
- Publicly revealing the invention before filing, which destroys novelty.
- Failing to clearly define the claims, leaving room for challenges.
- Skipping prior art searches, resulting in applications for technologies that already exist.
- Confusing a patent with a utility model and selecting the wrong legal route.
Examples of nullity due to lack of novelty or inventive step
Case 1 – Mobile technology (2018): A Spanish company filed a patent for a wireless charging system, but it was invalidated when it was shown that a Japanese academic article had disclosed the same technology six months earlier. Takeaway: Absolute lack of novelty is a direct cause for nullity.
Case 2 – Cosmetics sector (2021): An anti-aging cream formula was declared null because it merely combined ingredients already used in the industry without demonstrating an unexpected technical advantage. Legal basis: The invention was considered “obvious” to a professional in the field, negating the inventive step requirement.
Case 3 – Mechanical tool (Madrid High Court, 2020): A patent was revoked because the actual operation of the device did not match the technical description provided in the specification. Advice: Discrepancies between the invention and its description can render it legally ineffective and invalid.
Advanced strategies for protecting and monetizing your invention patent
Protecting a patent goes far beyond simply filing an application. To maximize its legal and commercial value, inventors and businesses must adopt a comprehensive strategy that combines legal safeguards, market positioning, and international protection.
Complement your patent with additional protection
A patent alone may not cover all aspects of your invention. Using complementary tools ensures stronger protection and prevents legal loopholes:
- Non-Disclosure Agreements (NDAs): Before even filing a patent, NDAs are crucial when sharing sensitive information with partners, engineers, investors, or potential collaborators. A carefully drafted NDA protects trade secrets during development and prevents unauthorized disclosure or copying of your technology.
- Industrial design and copyright: If your patented product includes a graphical interface, software, or a distinctive visual design, consider registering it as an industrial design or applying copyright protection. This ensures that the appearance and software components of your invention are legally safeguarded.
- Trademarks: Associating a trademark with your patented product reinforces its identity in the market. A recognizable brand differentiates your invention from competitors and adds commercial value, often becoming an essential part of your patent exploitation strategy.
Monetizing your patent: economic exploitation
Owning a patent does not mean you must produce or sell the invention yourself. There are several ways to generate revenue from your intellectual property:
- Licensing agreements: Licensing allows you to authorize third parties to use your invention in exchange for upfront payments or ongoing royalties. Licenses can be exclusive, granting rights to a single partner, or non-exclusive, enabling multiple market participants to operate simultaneously.
- Selling the patent: Selling your patent transfers full ownership to another party. It is essential to clearly define payment terms, rights transfer, and tax implications. In some cases, the sale of intangible assets like patents may qualify for tax incentives, depending on legal requirements.
- Joint ventures and technology transfer agreements: Patents can serve as a basis for strategic partnerships with other companies, research centers, or investment funds. Such collaborations often include contributions in kind, knowledge transfer, and joint development obligations, providing additional business opportunities and funding options.
International protection | Using the PCT system while filing patent for an invention
For inventors aiming to protect their invention globally, the Patent Cooperation Treaty (PCT) is a vital tool. While the PCT does not provide an “international patent,” it allows applicants to extend protection to over 150 member states efficiently. From the date of your first national application, you have 12 months to file a PCT application. This time can be used to seek investors, partners, or market validation before committing to specific countries.
The PCT system is especially useful for phased strategies. During the international phase, you receive an International search report and a preliminary patentability opinion, providing insight into the likelihood of success in key markets such as the U.S., Japan, China, or Germany. Additionally, the PCT procedure allows you to defer national fees for 18–30 months, giving extra time for technical validation, market analysis, or financing before entering national phases.
Why legal advice is important for patent registration
In conclusion, filing a patent for an invention may seem like a simple administrative process. However, even a small error in the drafting or procedure can result in the loss of rights, denial of the application, or, worse, allow a competitor to exploit your invention. Our law firm offers technical and legal expertise in all critical areas of patent protection, including:
- Drafting claims and detailed specifications: We prepare precise and comprehensive documentation to ensure maximum protection of your invention.
- Patentability analysis and prior art searches: We evaluate the novelty and feasibility of your invention through thorough searches of existing patents and technical literature.
- National, European, and international protection strategies: We design tailored strategies to secure your invention across multiple jurisdictions.
- Negotiation of licenses or technology transfer agreements: We assist in monetizing your patent through licensing deals or strategic transfers.
- Defense against oppositions or nullity actions: We represent your interests in case of legal challenges to your patent.
📩 Contact us to file a patent for an invention or custom legal advice on intellectual and industrial property at info@arthurmarin.com or at +32 465 345 345.
💡 Maximize the economic value of your invention, reduce legal risks, and achieve a long-term strategic vision.
