In this guide
What Are Technology Readiness Levels?
Technology Readiness Levels (TRL) are a 9-point scale developed by NASA in the 1970s and adopted by the European Commission as the standard framework for assessing how close a technology is to commercial deployment. Every Horizon Europe and EIC programme specifies eligible TRL ranges in its call text — applying at the wrong TRL is one of the most common reasons for instant rejection.
The TRL scale runs from TRL 1 (basic principles observed) to TRL 9 (technology proven in operational environment). Each level represents a distinct milestone in the journey from laboratory concept to market-ready product. The Commission uses TRL to match companies and research teams with the right funding instrument: early-stage research gets grants for exploration, mid-stage technologies get development funding, and near-market innovations get blended finance combining grants with equity.
Understanding TRL is not just a box-ticking exercise. Evaluators use your stated TRL as a credibility test. If you claim TRL 6 but cannot produce test data from a relevant environment, your proposal loses credibility on the Excellence criterion. If you claim TRL 4 but have paying customers, you are underplaying your maturity and might be applying to the wrong programme. Getting TRL right is the foundation of a well-targeted EU funding strategy.
The Commission defines TRL in the Horizon Europe General Annexes (Annex G). Always cite the official EU definition, not alternative scales used by national agencies or the defence sector, which may differ slightly.
TRL 1–3: From Basic Research to Proof of Concept
TRL 1 — Basic principles observed. You have identified a scientific phenomenon or formulated a hypothesis that could lead to a technology application. At this stage, you are doing fundamental research: publishing papers, running theoretical models, and exploring physical or computational principles. No application has been defined yet.
TRL 2 — Technology concept formulated. You have moved from "this phenomenon exists" to "this phenomenon could solve a specific problem." You have defined a potential application and begun exploring how the underlying science could be engineered into a working technology. Feasibility studies, literature reviews, and initial computational modelling typically characterise TRL 2.
TRL 3 — Experimental proof of concept. You have demonstrated that the core concept works in a laboratory setting. This is the critical transition from science to engineering — you have built something (however crude) that validates the fundamental mechanism. Key evidence includes laboratory measurements, initial prototypes (even non-functional ones that demonstrate the principle), and peer-reviewed publications describing experimental results.
For EU funding purposes, TRL 1–3 is the domain of the EIC Pathfinder, which provides grants of up to EUR 3–4 million for high-risk, visionary research. Pathfinder explicitly funds ideas that are too early and too uncertain for any other investor. The 2025 round funded 44 projects out of 2,087 applications — a 2.1% success rate — reflecting the programme's appetite for genuinely radical concepts. Horizon Europe Collaborative Research (Pillar II) also funds TRL 2–4 work through Research and Innovation Actions (RIAs), though these require multi-partner consortia from at least three EU countries.
If your technology is at TRL 2–3, EIC Pathfinder Open (no thematic restrictions, up to EUR 3M) or Pathfinder Challenges (thematic calls, up to EUR 4M) are your primary EU funding options. Check current Pathfinder calls for the latest deadlines.
TRL 4–5: Laboratory to Relevant Environment
TRL 4 — Technology validated in laboratory. Your technology has been tested as an integrated system in a laboratory environment. The difference from TRL 3 is integration: at TRL 3 you proved individual components work; at TRL 4 you have combined them into a functioning prototype and demonstrated that the integrated system performs as expected under controlled conditions. Evidence includes laboratory test reports, functional prototypes, and performance data against defined specifications.
TRL 5 — Technology validated in relevant environment. This is the first step outside the lab. "Relevant environment" means conditions that approximate real-world operating conditions — though not necessarily at full scale. For a biotech startup, this might mean testing in a bioreactor that mimics industrial conditions. For a hardware company, it could mean outdoor testing of a scaled-down prototype. For software, it means deployment in a testbed with realistic data volumes and user loads.
TRL 4–5 is the sweet spot for EIC Transition, which bridges Pathfinder research results and market-ready innovation with grants of up to EUR 2.5 million. Transition requires that you have outputs from a previous Pathfinder or ERC Proof of Concept project. The first EIC Transition Seals of Excellence were issued in February 2026 — 228 proposals received the Seal, meaning they scored above the quality threshold but could not be funded due to budget constraints.
Horizon Europe Innovation Actions (IAs) also fund TRL 4–6 work, typically in multi-partner consortia. IAs cover 70% of eligible costs for commercial entities (100% for non-profits) and focus on bringing research results closer to market through piloting, testing, and demonstration activities.
Documenting the transition from TRL 4 to TRL 5 requires evidence of testing outside laboratory conditions. Even a small-scale pilot in a real-world setting counts — customer site tests, field trials, or beta deployments all demonstrate TRL 5 maturity.
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Create Free AccountTRL 6–7: Demonstration and Prototype
TRL 6 — Technology demonstrated in relevant environment. Your technology has been demonstrated as a prototype system in an environment that represents realistic operating conditions. The key distinction from TRL 5 is scale and fidelity: at TRL 6, the prototype is close to the planned operational system in terms of performance, reliability, and form factor. This is typically where you have pilot installations, beta versions with real users, or pre-production manufacturing runs.
TRL 7 — System prototype demonstrated in operational environment. The technology works in its actual operating environment at or near full scale. For a medical device, this means clinical trials. For an industrial system, this means deployment in a real factory or plant. For software, this means production deployment with paying customers (even early ones). TRL 7 is the final validation step before productisation — you know it works in the real world, now you need to engineer it for manufacturing, scale, and support.
TRL 6–7 is the primary entry range for the EIC Accelerator, which provides up to EUR 2.5 million in grant funding and up to EUR 15 million in equity investment. The 2026 Work Programme introduced significant changes: full proposals are now 20 pages (down from 50), the minimum equity component is EUR 1 million (up from EUR 500,000), and there are six bimonthly cut-off dates throughout the year.
Evaluators will scrutinise your TRL claim carefully. At TRL 6, they expect to see pilot data, user feedback, and performance benchmarks. At TRL 7, they expect evidence of real-world deployment: customer testimonials, site visit reports, or independent testing results. The evidence must be specific and verifiable — "we tested with 3 industrial partners" is credible; "we plan to test soon" is TRL 5 at best.
The EIC Accelerator's 2026 Work Programme explicitly states the target TRL range as 5/6 to 8. If your technology is below TRL 5, consider EIC Transition or Pathfinder instead. Applying at the wrong TRL wastes one of your three permitted submissions.
TRL 8–9: Market Ready
TRL 8 — System complete and qualified. Your technology has been proven to work in its final form under expected operating conditions. All manufacturing processes are established, quality assurance is in place, and regulatory approvals (if applicable) have been obtained or are in advanced stages. The difference from TRL 7 is completeness: at TRL 8, there are no remaining technical risks, only commercial and scaling challenges.
TRL 9 — Actual system proven in operational environment. The technology is fully deployed, commercially available, and has a track record of successful operation. This is the end state — a product on the market with paying customers and operational data demonstrating reliability and performance at scale.
For EU funding purposes, TRL 8–9 is typically beyond the scope of R&D grants. However, several instruments support scaling at this stage:
The EIC Accelerator's equity component (up to EUR 15 million from the EIC Fund) explicitly targets the gap between technology completion and market scale-up. Companies at TRL 8 are strong EIC Accelerator candidates because they can demonstrate a working product while making a credible case for why they need public investment to scale.
The new STEP (Strategic Technologies for Europe Platform) Scale-Up instrument, launched in 2026 with EUR 300 million per year, provides investments of EUR 10–30 million per company for scaling deep tech in critical technology areas. InvestEU provides guarantee-backed venture debt and growth financing through financial intermediaries. And the EU Innovation Fund (separate from Horizon Europe, funded by Emissions Trading System revenues) provides grants for first-of-a-kind commercial deployments in clean technology.
If you are at TRL 8–9 and need EUR 10M+ for scaling, the new STEP Scale-Up instrument may be a better fit than EIC Accelerator. STEP targets critical technology areas including semiconductors, biotech, clean tech, and quantum, with investments of EUR 10–30M per company.
How to Assess and Evidence Your TRL
Evaluators do not take your TRL claim at face value. They look for evidence — and the type of evidence expected at each level is well defined in the European Commission's TRL guidance.
At TRL 1–2, evidence means peer-reviewed publications, theoretical models, and feasibility analyses. At TRL 3, you need laboratory test results and proof-of-concept data. At TRL 4–5, you need integrated system test reports, prototype performance data, and ideally independent verification. At TRL 6–7, you need pilot deployment data, user feedback, performance benchmarks against commercial specifications, and ideally letters from pilot sites or beta customers confirming real-world testing. At TRL 8–9, you need production specifications, regulatory certifications, customer contracts, and operational performance data.
A common mistake is conflating business progress with technology readiness. Having paying customers does not automatically mean TRL 9 if your product is still being manually configured for each deployment. Having a patent does not mean TRL 4 if you have never built a prototype. TRL measures the maturity of the technology itself, not the maturity of the business.
Another frequent error is presenting different TRL levels in different parts of the proposal. Your TRL claim in the technical section must be consistent with the evidence in your annexes, the development timeline in your work plan, and the budget allocation (if you are spending 70% of the budget on R&D, you are probably not at TRL 7).
The Horizon Europe 2026–2027 Work Programme uses a scoring system of 0–5 per evaluation criterion (Excellence, Impact, Implementation), with a minimum of 3 per criterion and a minimum of 10 total out of 15. Accurate TRL assessment directly affects your Excellence score — overstating or understating your readiness level undermines credibility on this critical criterion.
Create a TRL evidence table in your proposal with three columns: TRL Level Claimed, Evidence Available, and Where in the Proposal. This makes it easy for evaluators to verify your claim and demonstrates rigour. EUACC's application builder automatically generates TRL evidence matrices matched to your programme requirements.