LAST REVIEWED: OCTOBER 2026
By Dr Ritchie Lewis Daniel, Chartered Patent Attorney and European Patent Attorney
Before raising investment, you should be able to explain which parts of your technology are protected, who owns the rights and whether another party’s patents could affect your product plans. A list of patent numbers does not answer those questions.
A patent portfolio review connects your rights to the products and markets the investment will support. Checking early gives you time to address gaps before investors start IP due diligence. This is their examination of your IP assets and risks. These questions matter whether your business has one patent application or a portfolio built over several funding rounds.
Short on time?
Before investor IP due diligence, check these five points:
- Protection: Do your patents and applications cover the technology behind your current products and planned growth?
- Ownership: Does the company own, or have suitable licences to, the IP the business needs?
- Freedom to operate: Have you assessed the risk from other parties’ patents in your intended markets, before committing to tooling or launch?
- Deadlines and costs: Which filing decisions, deadlines and future costs need to be allowed for in the funding plan?
- Evidence: Can you support your IP position with documents and explain known gaps, disputes or restrictions?
Which products and markets need protection?
Start with your current products and the technology intended to support future growth. Funding a new product generation raises different questions from expanding sales of an established design.
Mechanical products change through development. Manufacturing constraints, testing and cost reduction can move the design away from the first prototype. An application prepared a year earlier may still be relevant, but that needs checking against the current engineering.
Establish which applications are pending, which patents have been granted and where rights remain in force. Check renewal or maintenance payments, the remaining patent term and any approaching deadlines. A patent close to expiry has a different relevance from one expected to remain in force throughout the planned product launch and growth period.
Compare the territorial position with the markets, manufacturing locations and competitors that matter to the business. A filing programme should have a commercial rationale for the countries selected.
Do your patents cover the product you are building?
Patent claims are the numbered statements that define the protection. For a granted European patent, they are interpreted using the description and drawings. An application’s claims show the protection being sought and may change during examination. A familiar-looking diagram or broad title is no substitute for reading the claims.
Consider a hypothetical lifting mechanism. The first prototype raises a load in a straight line. Later development produces a mechanism that raises the load along a spiral path.
An earlier claim limited to straight-line movement might miss the later design. A broader claim might cover both, depending on its interpretation and validity. You cannot add a claim specifically to the spiral version unless the original filing supports that change. A new application may be needed.
I would also ask you how a competitor could change the claimed features while retaining the benefit of the invention. Has a particular shape, material or arrangement become a limitation even though a competing product could use something else?
The commercial question is how readily a competitor could work around the claims. Protection can be valuable if a workaround means higher cost or inferior performance. A narrower claim may still matter if it protects a feature competitors need. The scope must remain justified by the original disclosure and earlier technology.
Related filings for the same invention can end up with different claims in different countries. Do not assume that the scope granted in one country has also been obtained elsewhere.
Could you tell whether a competitor was using the invention? A visible feature can be easier to check than one hidden inside a manufacturing process.
What can still be protected?
A pending application is not a granted patent, and grant is not assured. While an application is pending, there may be scope to adjust the claims around your commercial priorities. Amendments must stay within the original technical disclosure, and procedural restrictions apply. A granted European patent cannot be broadened by amendment.
A European divisional is a separate application that can pursue other protection supported by an earlier application, while that earlier application remains pending. It cannot add a later improvement missing from the original disclosure. The commercial benefit needs to justify the additional cost.
Search and examination reports help explain the protection that may be obtainable and the objections already raised. Any opposition or validity proceedings also matter, including amendments that changed the claims. Neither grant nor the absence of opposition establishes that a patent is commercially strong or immune from challenge.
Which filing deadlines need attention?
Later engineering developments may need a new application. Within the usual 12-month priority period from the first filing, a later application can claim that earlier date for the same invention already disclosed. Added improvements do not automatically get that earlier date. The original application cannot simply be topped up.
Applications normally publish around 18 months from the earliest filing or priority date. Before demonstrating a revised prototype, check whether new features need a further filing. Having filed once does not make later improvements safe to disclose. See also when a startup should file a patent application.
If using the Patent Cooperation Treaty (PCT) route for international protection, budget for entering the selected national or regional patent systems. Deadlines are often 30 or 31 months from the earliest priority date, or the filing date if no priority is claimed. Check the deadline for each office.
Does the company own the IP it needs?
A patent held personally by a founder does not automatically belong to the company seeking investment. Equally, ownership by a parent company, university or development partner may be deliberate. The question is whether the arrangements give the business the rights it needs.
Trace the position through the people and organisations that contributed. Check founder and employee inventions, consultant and supplier work, assignments (written transfers of rights) and collaboration terms. Work carried out before incorporation or for a previous employer may need particular attention. Inventorship and ownership are distinct: naming the inventors does not settle who should own the application.
The ownership position needs to be supported by the relevant agreements and development history. Paying a contractor does not, by itself, establish that the relevant rights have transferred.
Check licences granted to others as well as those on which the business relies. A licence may be limited to particular products or markets, or contain restrictions affecting a change of control. Security granted over IP and obligations to collaborators can also affect the company’s position.
Co-ownership deserves attention too. Clarify who can use the technology, license it, manage the filings and take enforcement action under the applicable law and agreements. The rules are not the same in every country.
Have you assessed freedom to operate?
Owning a patent does not establish freedom to operate. A business may have patentable technology and still encounter another party’s rights when making, importing or selling its product. Patentability and infringement are separate assessments.
A useful assessment needs a sufficiently defined product or feature, relevant territories and a proportionate scope. I would give particular attention to features that would be expensive or slow to redesign. Technically distinctive features may also warrant investigation, but commonplace components and combinations should not simply be assumed clear.
Plan the assessment when your technical approach is sufficiently clear, while you can still change the design.
Search an unsettled design too broadly and you may pay for work on arrangements you later abandon. Wait until tooling is ordered or the design is fixed and responding to a relevant patent may be more costly. Be clear which features and countries have been examined and which remain outside scope.
A search identifies potentially relevant documents. Assessing infringement risk requires analysis of the claims, legal status and intended activities. Relevant applications may still be unpublished at the search date, and pending claims can change. Neither a search nor an opinion provides a guarantee of non-infringement. Material changes to the product or target markets may require the assessment to be revisited.
Keep the wider IP position in view
Patents are only part of the review. Registered designs may be relevant to product appearance, trade marks to important brands, and copyright and licences to drawings and embedded software. Confidential manufacturing knowledge, test data and technical know-how can also matter.
A hardware business should understand which information must remain confidential and what it has agreed with development partners and manufacturers. Practical confidentiality and access controls matter alongside the contract wording. A patent-focused review can identify those connected issues and establish where further specialist work is warranted.
What should the review give you?
The review should help you explain to investors which rights protect important products, where gaps remain and what needs doing next. The practical output should be a prioritised action list, with responsibilities, timing and likely costs. Keep supporting records and identify any existing disputes or notices concerning third-party rights.
Some applications may justify further patent drafting or prosecution. Others may no longer warrant the cost of prosecution or renewal. A filing with no obvious link to today’s product should still be checked for a credible future, licensing or other strategic purpose before it is abandoned.
Territorial decisions should reflect realistic commercial opportunities alongside the cost of obtaining and maintaining useful rights. The initial filing is only part of the expenditure, as explained in the guide to patent costs.
For a scale-up preparing for a later funding round or acquisition, check that the documents shared with investors reflect the current portfolio, ownership and licences.
How do you start a review?
Start with your main products, target markets and investment timetable. RIDAN IP provides patent strategy and portfolio reviews for engineering and technology businesses, with a fixed fee where the work can be defined appropriately. Agree which products, rights and countries the review will cover and whether further searches or overseas advice are included.
Once conflicts and confidentiality arrangements have been addressed, useful starting documents include patent filings and patent-office reports, ownership and licence agreements, a product roadmap and records of important disclosures. These help focus the review on the decisions ahead.
A focused patent review can help prepare your company for IP due diligence. Wider transaction work may also require input from solicitors, trade mark attorneys or overseas advisers.
General information only. This article does not constitute legal advice. The discussion focuses on engineering and physical products in UK and European patent practice. The appropriate review depends on the technology, rights, territories and business circumstances.