What if London isn’t just the financial capital of Europe but also the quantum capital of the future? In hidden labs, startup hubs, and high-security R&D centres across the city, some of the world’s most brilliant minds are building machines that could one day break encryption, revolutionise medicine, and redefine computing itself. This isn’t science fiction. it’s quantum computing, and London is at the centre of it all.
From photonic pioneers to algorithmic trailblazers, a wave of innovative companies is transforming how the UK and the world thinks about processing power. In this blog, we’ll explore the top 10 quantum computing companies in London that are leading the charge into this mind-bending, multi-billion-pound industry.
Why Is London Emerging as a Quantum Computing Powerhouse?
London is quietly becoming Europe’s quantum capital and the world is starting to notice. The city’s fusion of elite universities, deep tech incubators, and powerful venture capital firms has created a launchpad for quantum computing innovation. As global demand for faster, smarter, and more secure computing grows, London-based startups and scaleups are carving out their place in the industry’s future.
Government investment, like the UK’s £1 billion National Quantum Technologies Programme, has given further momentum to this transformation. Combine that with the city’s talent-rich environment, and you have a powerful ecosystem where science meets business in the most groundbreaking ways.
What Makes a Quantum Computing Company Stand Out in 2025?
In 2025, it’s not enough for a quantum company to just publish academic papers. The most successful firms are building solutions that address real-world problems whether it’s simulating complex molecules for drug development or securing data in a post-quantum world.
What sets them apart is their ability to translate cutting-edge research into scalable technology. They’re creating commercial platforms, forming global partnerships, and bridging the gap between theory and enterprise. In today’s race, being ‘quantum ready’ means being market-ready too.
Which Are the Top 10 Quantum Computing Companies in London?
1. ORCA Computing – “Making quantum computing a practical reality”
ORCA Computing is redefining the future of scalable quantum systems with its innovative photonic-based technology. Headquartered in London, this trailblazing startup has taken quantum out of the cold lab and into real-world applications.
By harnessing quantum memory and photons, ORCA’s quantum systems operate at room temperature a game-changer in a field plagued by complexity and extreme cooling requirements.
In early 2025, the company rolled out 10 on-premise quantum photonic units, including high-profile deployments at the UK Ministry of Defence and the National Quantum Computing Centre (NQCC). These systems are actively used for machine learning, generative AI, and data optimisation.
Domain Expertise
End-to-end photonic quantum systems from chip-level design to enterprise-ready software
Ideal For
Organisations seeking compact, scalable quantum solutions for real-time simulation and optimisation
- Website: orcacomputing.com
- Phone: +44 2088116773
- Address: LG, 30 Eastbourne Terrace, London, W2 6LA, UK
- Email: media@orcacomputing.com
Review: ★★★★☆ Innovative product, with some employee concerns about management culture
2. Quantum Motion Technologies – “Quantum computing’s silicon moment”
Quantum Motion, a spinoff from UCL and Oxford, is leveraging the semiconductor industry to bring scalable quantum hardware to life. Its mission? To build high-performance quantum processors using the same silicon transistors found in today’s microchips.
The company’s approach promises high-density quantum chips that are easier to manufacture and integrate. In September 2025, Quantum Motion delivered its first silicon-based quantum system to the NQCC a significant leap forward in practical scalability.
Domain Expertise
Silicon-based quantum processors leveraging standard chip manufacturing
Ideal For
Enterprises looking to adopt quantum via CMOS-compatible infrastructure
- Website: quantummotion.tech
- Phone: +44 20 8146 2500
- Address: 9 Sterling Way, London, N7 9HJ, UK
- Email: webquery@quantummotion.tech
Review: ★★★★☆ Great team culture, but demanding work pace
3. Crypto Quantique – “Scalable IoT Security”
Crypto Quantique is making waves at the intersection of quantum physics and cybersecurity. Based in London, this company has developed a quantum-powered root-of-trust technology that protects IoT devices from future cyber threats. Their QuarkLink platform automates secure onboarding, device management, and cloud communication for millions of devices worldwide.
By embedding quantum randomness at the hardware level, Crypto Quantique is helping manufacturers design future-proof systems that can resist even post-quantum cyberattacks.
Domain Expertise
Quantum-powered cryptographic security for connected devices
Ideal For
IoT manufacturers and cloud service providers preparing for post-quantum threats
- Website: cryptoquantique.com
- Address: 164-180 Union Street, London SE1 0LH
- Email: info@cryptoquantique.com
Review: ★★★★☆ Strong tech reputation; known for industry innovation in IoT security
4. Phasecraft – “The pioneer in quantum software”
Phasecraft is on a mission to unlock the true power of quantum hardware by writing better quantum algorithms. This London-based company creates software that significantly reduces the computational resources needed for real-world quantum applications a must in the noisy, imperfect era of today’s quantum systems.
With partnerships across big names like Google and IBM, Phasecraft is developing software that speeds up breakthroughs in materials science, logistics, and quantum AI.
Domain Expertise
Quantum software for near-term devices (NISQ systems)
Ideal For
R&D teams, AI firms, and logistics companies exploring quantum solutions
- Website: phasecraft.io
- Address: 77-79 Charlotte Street, London, W1T 4PW, UK
- Email: info@phasecraft.io
Review: ★★★★★ Exceptional team culture and intellectually stimulating work
5. Post-Quantum – “Safeguarding your data against quantum attacks”
Post-Quantum isn’t building quantum computers. it’s making sure yours won’t be broken by one. Based in London, this firm is a global leader in quantum-safe cryptography, helping organisations transition to secure encryption models built to resist the computing power of the future.
The company’s hybrid cryptography solutions are already used by banks and defence agencies, and align with NCSC guidelines for post-quantum transition planning.
Domain Expertise
Quantum-resistant cryptographic systems and hybrid algorithm migration
Ideal For
Financial institutions, defence agencies, and security-focused enterprises
- Website: post-quantum.com
- Phone: +44 (0)20 8106 6913
- Address: 1 Harewood Row, London, NW1 6SE, UK
- Email: info@post-quantum.com
Review: ★★★★☆ Strong tech alignment with government security priorities
6. SEEQC UK – “Building the digital quantum computer”
SEEQC UK brings a new paradigm to quantum computing: fully digital quantum systems. Based in London, the company integrates quantum and classical control on a single chip using Single Flux Quantum (SFQ) technology, delivering low-latency, energy-efficient performance.
The company’s work is already attracting significant grant support. One notable project includes cancer therapy simulation, conducted in collaboration with Merck.
Domain Expertise
Integrated quantum classical architecture on superconducting chips
Ideal For
Pharma, manufacturing, and logistics firms exploring digital quantum applications
- Website: seeqc.com
- Phone: N/A UK; US HQ: 914-592-1190
- Address: Cargo Works, 1-2 Hatfields, London, SE1 9PG, UK
- Email: info@seeqc.com
Review: ★★★★☆ Strong R&D team and Innovate UK support
7. QuantGates – “Renaissance computation at work”
QuantGates is democratising access to quantum computing with a focus on education and easy-to-use software. Its London-based team offers both enterprise services and quantum workshops that empower professionals to build, test, and scale quantum applications without deep academic backgrounds.
Their flagship platform, Wolfgates, simplifies development across industries, particularly in finance and education.
Domain Expertise
Software, workshops, and platform tools for quantum adoption
Ideal For
Businesses new to quantum and universities launching quantum programmes
- Website: quantgates.co.uk
- Address: 86-90 Paul Street, London, EC2A 4NE, UK
- Email: info@quantgates.co.uk
Review: ★★★★☆ Widely respected for its training model and accessibility
8. Classiq UK – “Revolutionising quantum software development”
Originally from Israel, Classiq has expanded its presence to London, offering a unique platform that automates the journey from quantum algorithm design to execution. Their software helps developers even those without deep quantum expertise build efficient quantum circuits for multiple hardware platforms.
By abstracting the hard physics away from the user, Classiq enables more organisations to start quantum innovation without heavy R&D costs.
Domain Expertise
High-level quantum software development and circuit optimisation
Ideal For
Enterprises and developers integrating quantum into AI, ML, and analytics workflows
- Website: classiq.io
- Address: 77-79 Charlotte Street, London, W1T 4PW, UK
- Email: Via contact form
Review: ★★★★☆ Powerful software platform for non-physicist developers
9. Quantinuum – “A new era of computing”
Quantinuum, formed through the merger of Cambridge Quantum and Honeywell Quantum Solutions, has strong roots in the UK and a growing presence in London. With a full-stack offering from hardware to software and quantum cybersecurity. it’s one of the most complete players in the field.
Its cybersecurity product, Quantum Origin, is already redefining random number generation. Meanwhile, its TKET compiler and InQuanto chemistry platform are in use by major institutions across sectors.
Domain Expertise
Full-stack quantum computing including cybersecurity, chemistry, and AI
Ideal For
Defence, finance, and life sciences seeking end-to-end quantum tools
- Website: quantinuum.com
- Address: Carlisle Pl, London SW1P 1BX, United Kingdom
- Email: Via contact form
Review: ★★★★☆ Technically strong, with some concerns about its multinational alignment
10. Riverlane – “The quantum error correction company”
Riverlane, with a growing footprint in London, is tackling one of the biggest bottlenecks in quantum computing error correction. Their specialised software and hardware frameworks make today’s fragile qubits more stable and reliable.
In September 2025, Riverlane released Deltakit, a software development kit that allows researchers and developers to experiment with quantum error correction protocols.
Domain Expertise
Quantum error correction software and architecture
Ideal For
Hardware manufacturers and quantum R&D teams
- Website: riverlane.com
- Address: 1 Broadway Ste 14 Cambridge MA 02142 USA
- Email: team@riverlane.com
Review: ★★★★★ Collaborative team, respected by peers and partners
How Are These Companies Shaping the Future of Technology?
The impact of these London-based quantum firms extends far beyond the lab. They’re building technologies that could redefine industries. Take healthcare, for instance startups like Rahko have pioneered simulations that could speed up drug discovery by years.
In the financial world, companies like Quantinuum are working on algorithms that optimise complex portfolios and risk models in ways traditional computers can’t match.
Then there’s cybersecurity, where Cambridge Quantum is developing encryption methods built for the quantum age. Meanwhile, Nu Quantum is working on photonic technologies that could one day form the backbone of a secure quantum internet. From logistics and manufacturing to artificial intelligence, these firms are setting new standards for what’s technologically possible.
What Challenges Do Quantum Companies Face in London?
Even in a world-leading hub like London, building a quantum company isn’t easy. One major challenge is finding the right talent physicists and engineers with quantum experience are in short supply globally. Then there’s the issue of scalability. Designing a prototype is one thing; building a quantum processor that works reliably outside the lab is quite another.
Funding, though increasing, is still a bottleneck for companies beyond their seed stage. And public understanding remains low quantum computing is complex, and not every investor or potential partner truly grasps its value. Despite these hurdles, the momentum is undeniable, and London’s ecosystem is evolving to meet these challenges head-on.
What Role Does Collaboration Play in the Quantum Ecosystem?
Collaboration is one of London’s greatest strengths when it comes to quantum innovation. These companies aren’t operating in silos. Many are tightly connected to world-class institutions like Imperial College London, UCL, and Oxford. They collaborate with multinational partners, from tech giants like IBM and Honeywell to government-funded programmes through UKRI and Innovate UK.
These partnerships aren’t just about sharing knowledge they’re about accelerating commercial applications. Joint ventures help startups test and refine products faster, while academic ties provide access to talent and foundational research. This collaborative spirit has made London a place where quantum ideas quickly become market-ready products.
How Is the Quantum Landscape Expected to Evolve by 2030?
If the 2020s are about proving quantum’s potential, the 2030s will be about unleashing it. Analysts predict that by the end of the decade, quantum computing will be a standard tool in enterprise tech stacks, much like cloud computing today. London’s companies are laying the groundwork for that future right now.
We’ll likely see the rise of quantum cloud services, where businesses can tap into quantum power via APIs. There will be deeper integration with AI, as quantum algorithms optimise machine learning tasks. And as photonic and ion-trap technologies mature, we could witness the first commercially viable quantum networks possibly built by London startups already ahead of the curve.
Conclusion
There’s no doubt that London’s quantum computing companies are among the most promising players in global tech. They’re moving fast, thinking big, and redefining what’s possible in computing, cybersecurity, AI, and more. With continued support from universities, investors, and the government, these firms are positioned to lead not just a national movement but a global transformation.
For anyone watching the future of technology unfold, these are the names to know and the companies to follow. London isn’t just participating in the quantum race.it’s helping shape the track.
FAQs About Quantum Computing Companies in London
What is the UK doing to support quantum innovation?
The UK government has invested heavily in quantum research, with initiatives like the National Quantum Technologies Programme and support from UKRI and Innovate UK.
Are London quantum companies hiring international talent?
Yes, most leading quantum firms in London recruit globally, offering relocation packages and research roles for PhDs, engineers, and data scientists.
Which quantum startups in London focus on cybersecurity?
Cambridge Quantum is a leader in this space, developing encryption and key distribution methods for post-quantum security.
What role do London universities play in quantum development?
Institutions like UCL, Imperial College, and King’s College provide essential research, talent, and collaboration opportunities for quantum startups.
How close are we to real-world applications of quantum computing?
Several firms in London are already working on pilot projects with pharmaceutical, finance, and logistics companies, proving the early viability of quantum tech.
Can small businesses benefit from quantum computing?
As quantum-as-a-service platforms emerge, smaller businesses may soon access quantum computing via cloud APIs without large infrastructure costs.
Are quantum computers in London being used today?
Yes, although still limited in scale, some firms are testing quantum processors and running simulations on hardware prototypes or emulators.