Editorial Information
| Editorial Detail | Information |
|---|---|
| Published | 22 August 2026 |
| Last updated | 22 August 2026 |
| Research conducted | August 2026 |
| Options evaluated | 8 companies; 5 selected |
| Research methodology | Independent desk research using company websites, funding announcements, UK government and UKRI sources, university material, NQCC information and reputable independent reporting |
| Editorial disclosure | No paid placement or sponsorship influenced this ranking. We did not conduct hands-on technical testing of the companies’ quantum systems. |
Quick Answer
Quantum Motion is our top quantum computing startup in London to watch in 2026, primarily because it combines a differentiated silicon-spin architecture with strong manufacturing evidence, deployment at the UK’s National Quantum Computing Centre (NQCC) and a $160 million Series C announced in May 2026.
ORCA Computing ranks second for its unusually strong record of deploying photonic quantum systems into operational environments, while Phasecraft is the standout quantum-software company because of its hardware-agnostic algorithms and industrial partnerships. QMatter and SECQAI are earlier or less pure-play bets, but each addresses an important emerging part of the quantum stack.
Key Takeaways
- Best overall: Quantum Motion — strongest combination of capital, semiconductor manufacturability and hardware progress.
- Best for commercial photonic systems: ORCA Computing — notable for putting physical quantum systems into government, research and enterprise environments.
- Best quantum software startup: Phasecraft — focuses on practical algorithms for materials, chemistry, energy and optimisation.
- Emerging company to watch: QMatter — a young quantum-compression startup targeting life sciences and complex simulations.
- Best quantum-AI/security crossover: SECQAI — combines quantum algorithms with AI, semiconductors and confidential-computing technology.
Introduction
London’s quantum technology scene is no longer limited to university laboratories and early-stage research projects. Several companies now span silicon quantum hardware, photonic systems, quantum algorithms, artificial intelligence and specialist software designed to extract more value from imperfect quantum machines.
That makes identifying the most significant quantum computing startups in London more complicated than simply comparing funding totals. A well-funded hardware company and a small algorithm startup may be solving completely different bottlenecks.
For this ranking, we evaluated eight relevant companies and selected five on the basis of technical differentiation, commercial and technological progress, funding and scale, research partnerships, and contribution to London’s quantum ecosystem.
The timing is important. In March 2026, the UK government announced a package of support worth up to £2 billion for quantum technologies, including support for development and eventual procurement of large-scale quantum computers. In August 2026, Innovate UK also opened a competition offering up to £13 million for high-impact near-term quantum computing software applications.
The result is a list focused not on which company makes the boldest promises, but on why each company is worth watching now and what evidence supports that judgement.
Table of Contents
- How We Selected and Ranked the Startups
- Best Quantum Computing Startups at a Glance
- Detailed Comparison
- Best Startups by Use Case
- Funding and Commercial Access
- How to Evaluate a Quantum Startup
- London and the UK Quantum Ecosystem
- FAQs
- Conclusion
How We Selected and Ranked the Startups
This ranking is based on desk research conducted in August 2026. No first-hand laboratory testing, hardware benchmarking or private financial due diligence was performed.
To qualify, a business needed to have a meaningful London base or London headquarters and conduct substantive work directly related to quantum computing hardware, software, algorithms or closely integrated quantum-computing applications.
We evaluated eight candidates. Three notable companies did not make the final list:
- Rigetti Computing has a London office and significant UK activity, but its corporate headquarters are in Berkeley, California, and it is a NASDAQ-listed US company rather than a London startup.
- Riverlane is a highly important UK quantum-error-correction company but is headquartered in Cambridge rather than London.
- Oxford Ionics was excluded because it was acquired by IonQ in September 2025 and therefore no longer fits our definition of an independent startup; its centre of gravity is also Oxford rather than London.
Rating Methodology
We scored each selected company from 0 to 10 using the following model:
| Criterion | Weight |
|---|---|
| Technical differentiation | 30% |
| Commercial and technological progress | 25% |
| Funding and organisational scale | 20% |
| Research partnerships and evidence | 15% |
| London/UK ecosystem importance | 10% |
Scores are editorial assessments based on publicly available evidence, not measurements of absolute quantum-computer performance or predictions of investment returns.
Where two companies scored closely, we prioritised demonstrated deployment and commercial evidence.
Best Quantum Computing Startups at a Glance
| Rank | Startup | Best For | Core Approach | Latest Major Verified Milestone | Rating |
|---|---|---|---|---|---|
| 1 | Quantum Motion | Scalable quantum hardware | Silicon spin qubits / CMOS | $160m Series C, May 2026 | 9.6/10 |
| 2 | ORCA Computing | Commercial photonic systems | Photonic quantum computing | Enterprise PT Series deployment, June 2026 | 9.0/10 |
| 3 | Phasecraft | Quantum algorithms | Hardware-agnostic quantum software | $34m Series B, Sept. 2025 | 9.1/10 |
| 4 | QMatter | Quantum compression | Quantum/classical compression algorithms | $1.2m pre-seed, 2026 | 7.7/10 |
| 5 | SECQAI | Quantum AI and security | Quantum algorithms + semiconductors + AI | QLLM research and government-backed quantum programme | 7.2/10 |
Why ORCA ranks above Phasecraft despite the close scores: ORCA has stronger evidence of physical systems reaching customers and operational infrastructure. Phasecraft scores slightly higher mathematically but occupies a software layer where commercial quantum advantage still depends heavily on progress in third-party hardware.
Detailed Comparison
| Company | Founded | London Connection | Primary Technology | Funding Evidence | Commercial/Research Evidence |
|---|---|---|---|---|---|
| Quantum Motion | 2017 | London-based | Silicon spin qubits | $160m Series C in 2026 | NQCC system, GlobalFoundries partnership |
| ORCA Computing | 2019 | London HQ | Photonic quantum computing | $15m Series A publicly confirmed; substantial project funding | NQCC, private enterprise and international installations |
| Phasecraft | 2019 | London and Bristol offices | Quantum algorithms | $34m Series B in 2025; $50m+ total including grants | Google, IBM, Quantinuum, QuEra, NESO, BT and others |
| QMatter | 2024 | London/US operations; UCL origins | Quantum compression | $1.2m pre-seed in 2026 | Early life-sciences and simulation focus |
| SECQAI | 2021 | London-registered company | Quantum algorithms, AI and secure semiconductors | Government-funded R&D; private funding not clearly disclosed | Innovate UK, NATO DIANA, ChipStart UK |
Detailed Ranked Reviews
1. Quantum Motion — Best Overall
Quantum Motion takes first place because it addresses one of quantum computing’s hardest problems: how to manufacture very large numbers of qubits using technology capable of industrial-scale production.
Its approach uses silicon spin qubits designed around conventional semiconductor manufacturing processes. The company reinforced that thesis in 2025 by delivering a full-stack silicon CMOS quantum computer to the UK’s National Quantum Computing Centre and in May 2026 by raising $160 million in Series C funding.
Quick Facts
| Detail | Information |
|---|---|
| Founded | 2017 |
| Location | London, with additional international operations |
| Founders | Prof. John Morton and Prof. Simon Benjamin |
| CEO | James Palles-Dimmock |
| Technology | Silicon spin qubits using CMOS-compatible semiconductor processes |
| Latest major funding | $160m Series C, May 2026 |
| Academic origins | University College London and University of Oxford |
| Best for | Scalable silicon quantum computing |
Quantum Motion was founded as a spin-out from UCL and Oxford. The British Business Bank confirmed that it invested £40 million as part of the company’s $160 million Series C in May 2026.
Why We Ranked It First
Quantum Motion’s biggest distinction is not simply that it builds qubits from silicon. Its strategic advantage is the attempt to connect quantum-computer manufacturing to the enormous infrastructure already developed for conventional semiconductor fabrication.
In January 2025, the company announced that its Bloomsbury chip had been manufactured through GlobalFoundries’ commercial 300 mm semiconductor process. The chip integrated an array of 1,024 quantum dots, which Quantum Motion reported characterising in under five minutes.
Then, in September 2025, it delivered a full-stack silicon CMOS system to the NQCC. The deployment used a data-centre-oriented form factor based around three 19-inch server racks.
That progression—from semiconductor fabrication to complete system deployment to a major growth round—is why it ranks ahead of London’s other quantum startups.
Key Technology and Capabilities
Quantum Motion uses electron-spin qubits formed in silicon quantum dots. Its architecture is intended to be compatible with CMOS manufacturing, potentially allowing quantum processors to benefit from techniques developed over decades by the semiconductor industry.
Its NQCC system combines a quantum processing unit with control electronics, software interfaces and support for frameworks including Qiskit and Cirq.
The key opportunity is density: useful fault-tolerant quantum machines may ultimately require enormous numbers of physical qubits. A technology capable of manufacturing many quantum structures on compact silicon chips could therefore offer a meaningful scaling advantage.
Performance, Research and Market Evidence
Quantum Motion was selected as one of the providers for the NQCC’s £30 million quantum-computing testbed programme. The NQCC identifies its platform as the silicon-spin modality among the programme’s diverse hardware technologies.
The company has also worked with GlobalFoundries and progressed through DARPA’s Quantum Benchmarking Initiative. Its May 2026 financing will be used to push the technology further towards commercial deployment.
Funding
Verified latest round: $160 million Series C announced on 7 May 2026, co-led by DCVC and Kembara, with participation including the British Business Bank and existing investors.
This followed a £42 million Series B announced in 2023.
Pros
- Uses semiconductor processes with an established industrial supply chain.
- Delivered a complete silicon quantum system to the NQCC.
- Raised substantial growth capital in 2026.
- Strong UCL and Oxford academic roots.
- Clear focus on manufacturability rather than headline qubit counts alone.
Cons
- A deployed prototype does not yet prove economically useful fault-tolerant quantum computing.
- Silicon spin systems still face formidable control, fidelity and error-correction challenges at large scale.
- Several efficiency and cost advantages publicised by the company remain forward-looking company claims rather than independently established industry benchmarks.
Best For
Investors, researchers and technology leaders interested in quantum hardware startups with a semiconductor-manufacturing route to large-scale systems.
Editor’s Verdict
Quantum Motion currently has the strongest combination of technical differentiation, financing, credible manufacturing partnerships and deployed hardware among the London startups considered. The main trade-off is straightforward: its silicon thesis is compelling, but delivering a working system is not the same as demonstrating commercially valuable fault-tolerant computation at scale.
For readers looking specifically for the strongest hardware-focused London quantum startup in 2026, it is nevertheless the most convincing company on our evidence set.
Rating
9.6/10
2. ORCA Computing — Best for Commercial Photonic Quantum Systems
ORCA Computing earns second place because its strongest differentiator is not theoretical scale but deployability.
The London-headquartered Oxford University spin-out develops full-stack photonic quantum computers based on a modular fibre-connected architecture. Its systems have already reached government laboratories, universities and enterprise environments.
Quick Facts
| Detail | Information |
|---|---|
| Founded | 2019 |
| Headquarters | London |
| Founders | Prof. Ian Walmsley, Richard Murray and Josh Nunn |
| CEO | Richard Murray |
| Technology | Photonic quantum computing |
| Architecture | Modular, fibre-interconnected PT Series |
| Confirmed equity funding | $15m Series A announced in 2022; later financing is less transparent in primary sources reviewed |
| Best for | Deployable photonic quantum systems |
ORCA says it had delivered ten on-premises photonic systems worldwide by early 2025, including systems associated with the UK Ministry of Defence, NQCC, Poznan Supercomputing and Networking Center and Montana State University.
Why We Ranked It Second
Many quantum hardware companies are still primarily judged by laboratory benchmarks. ORCA deserves attention because it has repeatedly emphasised installation within existing computing environments.
In June 2025, it completed installation of a photonic quantum system at the NQCC.
In May 2026, ORCA joined Digital Realty’s London Innovation Lab, where its PT Series systems can operate alongside production-grade AI and data-centre infrastructure.
One month later, ORCA and Toyota Tsusho announced the installation of a PT Series quantum computer for a private-sector enterprise in Japan. ORCA said the system was deployed within a live enterprise environment in less than one week.
That deployment record gives ORCA one of the strongest commercialisation stories in this ranking.
Key Technology and Capabilities
ORCA’s architecture uses photons and quantum memory, alongside optical fibre and telecoms components. The company positions its systems as modular quantum accelerators that can work alongside classical HPC and AI infrastructure.
Its target applications include:
- optimisation;
- machine learning;
- generative AI;
- scientific computing;
- hybrid quantum-classical workloads.
ORCA has also developed a GPU-accelerated simulator for photonic systems using NVIDIA’s cuTensorNet technology.
Performance, Research and Market Evidence
ORCA was one of seven hardware companies selected for the NQCC testbed programme and represents one of the photonic modalities in the UK’s national testbed infrastructure.
Its wider partnerships have included BT, NVIDIA-related integration work and international research organisations. Its Quantum Data Centre of the Future programme was supported through an £11.6 million UK government-backed project involving a wide consortium of industry and academic participants.
Funding
ORCA publicly confirmed a $15 million Series A in June 2022.
Some current secondary databases report later Series B financing. However, because we did not locate an equivalent primary company or investor announcement confirming the reported amount during this research, we have not treated those figures as equally verified.
Pros
- Strong evidence of real-world hardware installations.
- Photonic architecture suited to integration with optical and data-centre infrastructure.
- London headquartered.
- Established relationships with government, research and enterprise organisations.
- Clear focus on hybrid quantum-AI and HPC workflows.
Cons
- Public disclosure around its latest equity financing is less clear than for Quantum Motion or Phasecraft.
- Photonic quantum computing still faces difficult scaling and fault-tolerance challenges.
- Commercial installations demonstrate accessibility and engineering maturity but do not by themselves establish quantum advantage over classical alternatives.
Best For
Enterprises and researchers interested in near-term access to physical photonic quantum systems and hybrid quantum-classical infrastructure.
Editor’s Verdict
ORCA is arguably the most deployment-oriented company on this list. Its systems have moved beyond laboratory demonstrations and into multiple operational environments, which is particularly important in a sector where commercial readiness often lags behind scientific ambition.
Quantum Motion ranks higher because of its scale-up financing and semiconductor manufacturing thesis. Readers more interested in systems that organisations can experiment with now, however, may find ORCA the more immediately relevant company.
Rating
9.0/10
3. Phasecraft — Best for Quantum Algorithms
Phasecraft is the highest-ranked pure quantum-software company in our selection.
Rather than committing to one type of quantum processor, the London- and Bristol-based company develops hardware-agnostic algorithms intended to squeeze useful calculations from current and emerging quantum machines.
In September 2025, Phasecraft raised $34 million in Series B funding, taking its total funding to more than $50 million when grants are included.
Quick Facts
| Detail | Information |
|---|---|
| Founded | 2019 |
| Locations | London, Bristol and Washington DC |
| Founders | Prof. Toby Cubitt, Prof. Ashley Montanaro and Prof. John Morton |
| CEO | Ashley Montanaro |
| Technology | Quantum algorithms and software |
| Latest major funding | $34m Series B, September 2025 |
| Academic origins | UCL and University of Bristol |
| Best for | Practical quantum algorithms |
Phasecraft maintains offices in London and Bristol and grew from academic work associated with UCL and the University of Bristol.
Why We Ranked It Third
Quantum hardware receives most of the attention in the industry, but hardware is valuable only if useful algorithms can operate within its constraints.
Phasecraft focuses precisely on that problem.
Its algorithms target materials discovery, chemistry, energy networks and optimisation. More importantly, the company works across multiple hardware ecosystems rather than betting on a single qubit architecture.
Phasecraft has cited collaborations with Google Quantum AI, IBM, Quantinuum and QuEra, while industry-facing work includes Johnson Matthey, Oxford PV, the UK’s National Energy System Operator and BT.
Key Technology and Capabilities
Phasecraft’s core proposition is resource efficiency.
Quantum computers have limited qubit counts, imperfect gates and substantial noise. Reducing the number and depth of operations required by an algorithm can therefore materially change whether a problem is practical on a given machine.
Its work includes:
- quantum simulation;
- materials modelling;
- chemistry;
- optimisation;
- energy-system problems;
- techniques designed for noisy and near-term hardware.
Performance, Research and Market Evidence
The company’s academic origins are unusually strong. Its founders have research backgrounds spanning quantum information and quantum computation at UCL and Bristol.
The University of Bristol reports that Phasecraft’s industrial work includes applications involving materials, biochemical processes and energy networks.
Its partnerships across multiple hardware companies also provide a form of strategic diversification: if one qubit modality progresses faster than another, Phasecraft’s hardware-independent model may allow it to adapt.
Funding
Phasecraft announced a $34 million Series B on 2 September 2025, co-led by Plural, Playground Global and Novo Holdings’ Quantum Fund, with existing investors also participating.
The company and university sources reported total financing of more than $50 million including grants after the round.
Pros
- Hardware-agnostic business model.
- Strong academic founding team.
- Significant Series B financing.
- Partnerships with several major quantum hardware providers.
- Clear industrial use cases rather than generic quantum software.
Cons
- Commercial success remains tied to improvements in third-party quantum hardware.
- Quantum advantage for many targeted applications has not yet become routine.
- Its value can be harder for non-specialists to measure than the deployment of a physical machine.
Best For
Enterprises, researchers and investors interested in quantum software, algorithms, materials science, optimisation and hardware-independent technology.
Editor’s Verdict
Phasecraft may ultimately prove just as strategically important as London’s hardware companies because efficient algorithms are essential to turning qubit improvements into useful applications.
It ranks third rather than second primarily because ORCA has stronger evidence of physical systems reaching operational customers. For readers interested specifically in quantum algorithms and near-term applications, Phasecraft is our strongest choice.
Rating
9.1/10
4. QMatter — Best Emerging Quantum Compression Startup
QMatter is much younger than the top three companies, but its timing and technical focus make it one of London’s more interesting emerging quantum technology startups.
The company is developing what it calls quantum compression: reducing complex simulation problems before sending them to quantum or conventional computing hardware.
Quick Facts
| Detail | Information |
|---|---|
| Founded | 2024 |
| Base | London/US operations with UCL origins |
| Co-founders | Dr Alexis Ralli and Dr Timothy Weaving, with Prof. Peter Coveney and Prof. Peter Love as academic co-founders |
| Technology | Quantum compression |
| Latest funding | $1.2m pre-seed, 2026 |
| Primary applications | Life sciences, materials simulation and physics-informed AI data |
| Best for | Early-stage quantum compression technology |
QMatter’s founders developed expertise in quantum computing, quantum chemistry and molecular modelling through work connected to University College London.
Why We Ranked It Fourth
Today’s quantum computers are constrained by limited usable qubits and noise. One solution is better hardware. Another is to reduce the computational problem before it reaches the hardware.
QMatter is pursuing the second strategy.
According to the company, its algorithms use a quantum latent space intended to retain important quantum characteristics while producing a more compact representation of an industrial-scale problem. Its platform is designed to run across hardware ranging from conventional computers to supercomputers and quantum processors.
This is an appealing concept because it potentially creates value before large fault-tolerant quantum computers exist.
Technology and Applications
QMatter’s early commercial focus is particularly relevant to:
- drug discovery;
- pharmaceutical R&D;
- materials science;
- molecular simulation;
- physics-informed machine-learning datasets.
The company says the same compression techniques may help both classical and quantum systems rather than requiring customers to wait for future fault-tolerant hardware.
Funding and Market Evidence
QMatter raised $1.2 million in pre-seed financing in 2026, led by 55 North, with participation reported from XTX Ventures, Bellstate Oy and the Conception X Angel Syndicate.
That capital is modest compared with the top three companies, but QMatter is also at a much earlier development stage.
Key Limitation
Evidence of the company’s technology currently comes predominantly from QMatter itself and early-stage industry reporting.
We did not find enough independently published large-scale performance benchmarks or mature customer deployments to place QMatter alongside Phasecraft yet.
That is precisely why it is a company to watch, rather than one we would describe as commercially established.
Pros
- Tackles a genuine near-term quantum resource problem.
- Can potentially create value across both quantum and classical hardware.
- Strong academic foundations in quantum chemistry and molecular modelling.
- Clear focus on life-sciences applications.
- Fresh 2026 pre-seed financing.
Cons
- Very early-stage company.
- Limited publicly documented commercial deployment.
- Independent benchmarking of its compression platform remains limited.
- Significantly smaller funding base than the leading companies.
Best For
Readers tracking very early quantum-software startups focused on drug discovery, molecular modelling and resource-efficient computation.
Editor’s Verdict
QMatter is the speculative entry in the ranking.
Its compression-first approach is intellectually compelling because it attacks the mismatch between industrial problem sizes and today’s limited computing resources. What it does not yet have is the depth of public commercial and benchmarking evidence available for Quantum Motion, ORCA or Phasecraft.
Progress with pharmaceutical partners, measurable compression benchmarks and larger funding rounds would materially strengthen its position in future rankings.
Rating
7.7/10
5. SECQAI — Best for the Quantum-AI and Security Crossover
SECQAI is the hardest company in this list to categorise.
It is not a pure-play quantum-computing startup. Instead, the London company works across secure semiconductors, confidential computing, artificial intelligence, post-quantum security and quantum algorithms.
We include it because its government-backed quantum-AI research and Quantum Large Language Model project give it a meaningful connection to London’s quantum-computing ecosystem.
Quick Facts
| Detail | Information |
|---|---|
| Incorporated | 2021 |
| Registered office | London |
| Founder/CEO | Rahul Tyagi |
| Primary business | Secure semiconductors and confidential computing |
| Quantum work | Quantum algorithms, quantum NLP and hybrid quantum-AI |
| Government-supported R&D | Innovate UK quantum NLP project |
| Best for | Quantum-AI and security convergence |
Companies House records SECQAI Ltd as an active company incorporated in June 2021 with a London registered office.
Why We Ranked It Fifth
SECQAI’s most relevant quantum programme centres on applying quantum methods to natural-language processing and AI.
UKRI’s Gateway to Research records an Innovate UK-backed project titled “A novel, quantum model for NLP: a step towards AGI”, with funding of approximately £310,000 involving SECQAI.
SECQAI subsequently announced a hybrid Quantum Large Language Model (QLLM) in February 2025. The company described it as the world’s first QLLM; we treat that wording as a company claim rather than an independently established industry record.
Key Technology and Capabilities
Its quantum activity sits alongside a broader secure-computing stack incorporating semiconductor design, post-quantum cryptography and AI.
That creates an unusual combination of:
- quantum algorithms;
- natural-language processing;
- quantum machine learning;
- semiconductor engineering;
- post-quantum security;
- confidential computing.
The company has also participated in NATO DIANA and the UK government’s ChipStart UK semiconductor programme.
Research and Commercial Evidence
Government documentation provides meaningful independent evidence that SECQAI has participated in funded quantum R&D.
What is less clear is the commercial maturity of its quantum-computing products specifically.
SECQAI has stronger public evidence around secure semiconductor products and post-quantum security than around broadly deployed quantum-computing applications. Its QLLM was initially announced for private beta access.
Funding
SECQAI’s venture-funding total is not publicly disclosed in sources we could verify.
Its public-sector support includes the Innovate UK-backed quantum NLP programme and other government-supported AI and semiconductor initiatives. UK government material also records £100,000 of support for an earlier low-power AI technology project.
Pros
- Distinctive overlap of quantum, AI and semiconductor technology.
- Verifiable UK government-supported quantum research.
- Active London company.
- Participation in NATO DIANA and ChipStart UK.
- Potential exposure to both quantum computing and post-quantum security trends.
Cons
- Not a pure-play quantum computing company.
- Public commercial evidence for its quantum algorithms is limited.
- QLLM performance has not been independently benchmarked sufficiently for broad conclusions.
- Private funding information is relatively opaque.
Best For
Readers interested in the intersection of quantum machine learning, secure computing, AI and semiconductor technology.
Editor’s Verdict
SECQAI earns its place because London’s quantum ecosystem extends beyond companies building general-purpose quantum processors.
Its quantum-AI research is credible enough to watch, particularly given government-supported work. However, the company’s wider emphasis on secure computing means readers looking specifically for a pure-play quantum-computing investment or supplier should consider Quantum Motion, ORCA, Phasecraft or QMatter first.
Rating
7.2/10
Best Startups by Use Case
Head-to-Head Comparison
| Use Case | Winner | Why |
|---|---|---|
| Best overall London quantum startup | Quantum Motion | Strong combination of funding, manufacturing strategy and hardware deployment |
| Best quantum hardware for near-term deployment | ORCA Computing | Multiple on-premises photonic systems and enterprise integration |
| Best quantum software company | Phasecraft | Hardware-agnostic algorithms and major research/industry partnerships |
| Best emerging startup | QMatter | Early-stage quantum compression approach with life-sciences potential |
| Best quantum-AI crossover | SECQAI | Government-backed quantum NLP and hybrid AI research |
| Best semiconductor approach | Quantum Motion | Leverages established CMOS manufacturing infrastructure |
| Best for industrial algorithms | Phasecraft | Materials, chemistry, energy and optimisation focus |
| Best for hybrid AI infrastructure | ORCA Computing | Strong photonic, GPU and data-centre integration strategy |
Funding and Commercial Access Comparison
These companies do not sell consumer products, so conventional retail pricing is not useful. Commercial access, financing and deployment maturity provide a more meaningful comparison.
| Company | Latest Funding Evidence | Commercial Access | Maturity |
|---|---|---|---|
| Quantum Motion | $160m Series C, May 2026 | Direct partnerships / institutional deployments | Scale-up |
| ORCA Computing | $15m Series A publicly confirmed; substantial grants and later financing reports | Direct system deployments and enterprise projects | Commercialising |
| Phasecraft | $34m Series B, Sept. 2025 | Enterprise and research collaborations | Scale-up software |
| QMatter | $1.2m pre-seed, 2026 | Register-interest / partnership model | Early stage |
| SECQAI | Venture total not publicly verified; government-backed R&D | Partner-led/private access for quantum work | Early-to-growth deep tech |
Pricing checked in August 2026: none of the five companies publishes standard public pricing comparable with conventional SaaS subscriptions. Where pricing is required, organisations should request current commercial terms directly rather than relying on estimates.
How to Evaluate a Quantum Computing Startup
1. Start With the Quantum Modality
“Quantum computing company” covers fundamentally different technologies.
Quantum Motion uses silicon spin qubits. ORCA uses photons. Phasecraft and QMatter primarily develop software and algorithms. SECQAI combines quantum methods with AI and semiconductor technology.
The most promising company therefore depends on which part of the quantum stack matters to you.
2. Look Beyond Qubit Counts
Headline qubit numbers are easy to understand but can be poor standalone indicators of useful performance.
Gate fidelity, error rates, connectivity, circuit depth, calibration, control architecture and error correction all matter. A smaller high-quality processor may be more useful than a much larger noisy system for some workloads.
3. Separate Deployment From Quantum Advantage
Installing a quantum computer at a customer site is an important commercial milestone.
It does not automatically prove that the system beats the best classical alternative on an economically meaningful task.
Those are separate achievements and should be evaluated separately.
4. Examine the Route to Scale
For hardware startups, ask what happens if the company needs hundreds of thousands or millions of physical qubits.
Quantum Motion’s use of semiconductor manufacturing is therefore strategically important. ORCA approaches scalability differently through photonics and modular optical architecture.
5. Evaluate Software Independence
Algorithm companies face a different question: how dependent are they on a particular hardware architecture?
Phasecraft’s hardware-agnostic model potentially provides diversification across competing qubit technologies.
6. Demand Independent Evidence
Company announcements are useful primary sources for products, partnerships and corporate milestones, but technical performance claims should ideally be reinforced through peer-reviewed publications, independent benchmarking or credible institutional evaluation.
This matters particularly for young companies making very ambitious claims.
7. Treat Funding as Evidence, Not Proof
A large venture round shows that sophisticated investors are willing to finance the company’s roadmap.
It does not prove that the technology will succeed.
Quantum computing remains a technically risky industry in which commercial timelines depend on scientific advances that are inherently difficult to predict.
London and the Wider UK Quantum Ecosystem
The five startups matter partly because they operate within a national quantum ecosystem that has become substantially more ambitious.
The UK’s National Quantum Strategy established a long-term objective of building a leading quantum-enabled economy, supported by substantial public investment. The country’s quantum-computing mission calls for accessible UK-based quantum computers capable of running one trillion operations by 2035, together with useful applications across sectors including healthcare, finance, energy, transport and manufacturing.
The policy environment expanded again in March 2026 when the government announced support worth up to £2 billion. UKRI described this as part of a full-stack approach spanning quantum hardware and software, with the NQCC and Quantum Software Lab playing central roles in testing and validation.
London contributes an unusually broad mix to that landscape.
Quantum Motion represents silicon quantum hardware. ORCA represents photonics. Phasecraft supplies algorithms. QMatter explores problem compression. SECQAI connects quantum methods with AI and semiconductors.
The NQCC’s testbed programme is particularly important because it gives UK developers an environment in which different architectures can be independently evaluated. Seven testbeds across five technology modalities were deployed as part of a £30 million programme, including systems from Quantum Motion and ORCA Computing.
The government’s current strategy also increasingly emphasises applications rather than hardware alone. An Innovate UK competition opened on 4 August 2026 offering up to £13 million for software applications capable of delivering high-impact value from near-term quantum computers.
That shift could favour London’s mixture of hardware, software and hybrid computing companies rather than any single technological approach.
Frequently Asked Questions
What are the best quantum computing startups in London?
Based on our August 2026 research, the five London quantum companies most worth watching are Quantum Motion, ORCA Computing, Phasecraft, QMatter and SECQAI.
Quantum Motion ranks first because of its silicon-spin architecture, full-stack NQCC deployment and $160 million Series C. ORCA stands out for photonic-system deployments, while Phasecraft is particularly strong in quantum algorithms.
Which London startup is building an actual quantum computer?
Quantum Motion and ORCA Computing both build physical quantum-computing systems.
Quantum Motion develops silicon-spin quantum computers using CMOS-compatible semiconductor processes. ORCA Computing develops photonic quantum computers based on photons, optical fibre and quantum-memory technology. Both have delivered systems into the UK’s NQCC programme.
Which London quantum startup has raised the most recent major funding?
Among the companies reviewed, Quantum Motion has the largest recent verified round, announcing a $160 million Series C on 7 May 2026.
The British Business Bank contributed £40 million to the round.
Is Phasecraft a quantum computing hardware company?
No. Phasecraft is primarily a quantum algorithms and software company.
Its strategy is to develop resource-efficient algorithms capable of operating across multiple hardware architectures rather than building a quantum processor itself. Its partnerships include companies developing different quantum-computing modalities.
What is photonic quantum computing?
Photonic quantum computing uses particles of light—photons—to encode and manipulate quantum information.
ORCA Computing is the main photonic company in this London ranking. Its approach combines photonic processing, quantum memory and fibre-connected architecture with the goal of integrating quantum resources into existing computing infrastructure.
What is silicon quantum computing?
Silicon quantum computing attempts to create quantum processors using silicon-based devices and semiconductor-manufacturing techniques.
Quantum Motion uses the spin of individual electrons within silicon quantum-dot structures as its qubit approach. The potential advantage is compatibility with the enormous manufacturing ecosystem already used to produce conventional silicon electronics.
Are quantum computers commercially useful yet?
They are increasingly useful for research, experimentation, algorithm development and quantum-readiness programmes, but broad commercial quantum advantage remains limited.
The NQCC is now independently testing multiple hardware platforms precisely because comparing real system performance and determining where quantum technology delivers useful advantages remains an active technical challenge.
Claims that quantum computers can already replace conventional supercomputers across mainstream workloads should therefore be treated cautiously.
Is London a major quantum technology hub?
Yes, although the broader UK quantum ecosystem also has important clusters in Oxford, Cambridge, Bristol and elsewhere.
London is particularly notable because it hosts companies operating at several levels of the quantum stack, from Quantum Motion’s hardware and ORCA’s photonic systems to Phasecraft’s algorithms and specialist startups such as QMatter and SECQAI.
Conclusion
London’s most interesting quantum companies are pursuing very different answers to the same fundamental question: how can quantum computing progress from impressive physics to useful computation?
For 2026, Quantum Motion is our best overall startup to watch. Its combination of silicon semiconductor manufacturing, NQCC deployment and a $160 million Series C gives it the strongest overall evidence base.
ORCA Computing is the leading alternative for readers interested in deployable photonic systems and hybrid quantum infrastructure, while Phasecraft is arguably London’s most important specialist quantum-software company.
The companies lower in the ranking should not be dismissed. QMatter could become important if quantum compression proves valuable for life-sciences simulations, while SECQAI provides exposure to the increasingly relevant overlap between quantum algorithms, artificial intelligence and secure semiconductors.
The key consideration is not simply which startup has the highest funding or most ambitious roadmap. Watch for independently validated technical progress, repeatable customer deployments, improvements in fault tolerance and evidence that quantum systems or algorithms produce useful results on real industrial problems.
Those signals will determine which of today’s London quantum startups become enduring technology companies.
Editorial Disclosure
This ranking was produced through independent desk research conducted in August 2026 using official company information, UK government and UKRI sources, university publications, NQCC material and reputable independent reporting. We did not perform hands-on testing of quantum hardware or independently audit private financial information. Company-reported technical claims are identified or qualified where independent verification is limited. Rankings reflect the published editorial methodology and were not influenced by paid placement, sponsorship or affiliate relationships.