Times have changed and cybersecurity isn’t just a buzzword anymore, it’s a daily concern. UK businesses, big or small, are dealing with an endless stream of threats malware, data leaks, misconfigurations, and the occasional insider slip. Off-the-shelf tools can help, but they rarely give the full picture of where your systems are exposed. That’s where dedicated security testing comes in.
In this guide, we’ll look at some of the leading security testing companies in the UK. These are teams who spend their days poking at applications, infrastructure, and networks to find weaknesses before attackers do. Whether you’re a startup building your first product or an established enterprise managing sensitive data, knowing which providers are out there can make all the difference when it comes to staying ahead of the risks.
1. A-Listware
We’re A-Listware, and most of what we do comes down to making technology work the way it should for businesses. Sometimes that means joining up systems that were never designed to connect, other times it’s about tightening up security so nothing slips through the cracks. We spend a lot of time digging into the details, making sure data moves where it needs to go and risks get spotted before they turn into real problems.
Working with UK clients, we’ve seen plenty of setups that mix older systems with newer tools. Our job is to bring some order to that mix so teams aren’t stuck firefighting or juggling half a dozen platforms at once. That might be through fresh integrations, modernising what’s already there, or running penetration tests to highlight weaknesses. However the project looks, the aim stays the same: keep things simple, reliable, and secure enough to handle day-to-day business without extra hassle.
Key Highlights:
- Software development and integration company
- Works with UK clients across industries
- Deals with both older legacy systems and new builds
- Focus on practical fixes over jargon
- Combines development with security testing
Services:
- Custom software development
- API and system integration
- Legacy system upgrades
- Security testing and assessments
- Web and mobile connectivity
- Long-term support and maintenance
Contact Info:
- Website: a-listware.com
- Email: info@a-listware.com
- Facebook: www.facebook.com/alistware
- LinkedIn: www.linkedin.com/company/a-listware
- Address: St. Leonards-On-Sea, TN37 7TA, UK
- Phone Number: +44 (0)142 439 01 40
2. Redscan
Redscan is a UK cybersecurity company that spends its time looking for weak points in systems before attackers do, their approach is fairly straightforward: simulate real threats, check how defenses hold up, and then provide clear advice on where the gaps are. They work with both infrastructure and applications, so the focus isn’t just on one layer but across the board. They also run continuous monitoring for clients who don’t just want a one-off test which would entail keeping an eye on networks, endpoints, and cloud environments to spot issues as they appear. It’s not about fancy labels, more about making sure that businesses can identify and fix problems early, without being caught off guard.
Key Highlights:
- UK-based cybersecurity provider
- Focus on penetration testing and threat detection
- Covers infrastructure, applications, and cloud setups
- Provides ongoing monitoring, not just one-time audits
- Works with organizations across different sectors
Services:
- Penetration testing
- Red team operations
- Managed detection and response
- Threat intelligence
- Cloud security assessments
- Security awareness training
Contact Info:
- Website: www.redscan.com
- Email: info@redscan.com
- Phone: +442039722500
- Address: Kroll, Level 6, The News, 3 London Bridge Street, London, SE1 9SG UK
- LinkedIn: www.linkedin.com/company/redscan
- Twitter: x.com/Redscan
3. Evalian
Evalian is a UK company that focuses on helping businesses handle cybersecurity and data protection in a practical way. They don’t just run tests and leave you with a long report to figure out. Instead, their work tends to combine assessments, advice, and hands-on support so organizations can actually act on the findings. That can mean reviewing security setups, checking compliance with privacy rules, or running exercises to see how teams respond to real incidents.
Their approach leans more toward being an extra set of experienced eyes rather than just dropping technical jargon. They cover different areas of security, from penetration testing and risk reviews to GDPR support and training. The idea is to give companies a clearer view of where they stand and what they need to work on without overcomplicating things.
Key Highlights:
- UK-based consultancy with a focus on security and privacy
- Mixes technical testing with compliance and advisory work
- Helps companies prepare for regulations like GDPR
- Offers training alongside assessments
- Works with organizations across various industries
Services:
- Penetration testing
- Cybersecurity risk assessments
- GDPR and data protection support
- ISO 27001 consultancy
- Incident response planning
- Security awareness training
Contact Info:
- Website: evalian.co.uk
- Email: hello@evalian.co.uk
- Phone: 03330500111
- Address: West Lodge, Leylands Business Park, Colden Common, Hampshire, SO21 1TH U.K.
- LinkedIn: www.linkedin.com/company/evalian
4. The Cyphere
The Cyphere is a UK security company that spends most of its time running penetration tests and helping organizations understand their real-world risks. Their work usually starts with identifying weaknesses in networks, applications, or cloud setups and then breaking down what those issues actually mean in plain terms. The focus isn’t only on the technical details but on making sure clients know what needs fixing and why it matters.
They also step in on the advisory side, offering guidance around compliance, policies, and longer-term security planning. Instead of just handing over a report and moving on, they stick around to explain the results and help companies work through the changes. It’s less about ticking boxes and more about making sure security practices fit into how a business actually operates.
Key Highlights:
- UK-based security testing and advisory company
- Strong focus on penetration testing across systems and applications
- Works with both cloud and on-premises environments
- Provides compliance and governance support
- Known for explaining findings in a practical, non-technical way
Services:
- Penetration testing
- Cloud security assessments
- Network and infrastructure reviews
- Security risk and compliance consulting
- Policy and procedure development
- Ongoing security advisory
Contact Info:
- Website: thecyphere.com
- Email: info@thecyphere.com
- Phone: 0333 050 9002
- Address: 71-75, Shelton Street,Covent Garden,London, WC2H 9JQ
- LinkedIn: www.linkedin.com/company/thecyphere
- Twitter: x.com/TheCyphere
5. JUMPSEC
JUMPSEC is a UK-based cybersecurity company that puts a lot of effort into helping organizations understand where they’re vulnerable and how to deal with it. They carry out penetration testing and other checks to spot weaknesses before attackers do, but their work doesn’t stop there. They also help companies plan how to respond when something goes wrong, so it’s not just about prevention but also about being prepared for the messier side of incidents.
What stands out is how they try to make the process less of a box-ticking exercise. Instead of throwing out technical reports no one reads, they focus on breaking down risks in a way teams can act on. That could be through red team exercises, advisory work, or building stronger internal processes. The end goal isn’t to drown people in jargon but to make sure security fits into how the business actually runs day to day.
Key Highlights:
- UK-based cybersecurity company
- Focus on penetration testing and red team exercises
- Helps companies prepare for and respond to incidents
- Works across technical testing and advisory support
- Practical approach with less jargon and more usable outcomes
Services:
- Penetration testing
- Red team operations
- Incident response planning
- Security strategy and advisory
- Vulnerability assessments
- Ongoing security monitoring
Contact Info:
- Website: www.jumpsec.com
- Email: hello@jumpsec.com
- Phone: 0333 939 8080
- Address: Unit 3E – 3F, 33 – 34 Westpoint, Warple Way, Acton W3 0RG UK
- LinkedIn: www.linkedin.com/company/jumpsec
- Twitter: x.com/JUMPSEC
6. SE Labs
SE Labs is a UK company that focuses on testing security products to see how they really hold up against threats. Instead of just taking vendors at their word, they run independent assessments and publish results that show what works and what doesn’t. Their work is aimed at giving businesses and users a clearer idea of how different security tools actually perform in practice.
They don’t just stop at reports though. SE Labs also provides consultancy and tailored testing for organizations that want to understand how their own setups react to different types of attacks. The goal isn’t to make things more complicated but to cut through the noise and provide information that’s actually useful when choosing or improving security systems.
Key Highlights:
- UK-based independent security testing company
- Runs assessments on commercial security products
- Provides consultancy and custom testing services
- Publishes reports to show real-world performance
- Focuses on practical results over marketing claims
Services:
- Independent security product testing
Custom security assessments - Threat simulation and evaluation
- Security consultancy
- Reporting and analysis for businesses and vendors
Contact Info:
- Website: selabs.uk
- Email: info@selabs.uk
- Address: 4 Cromwell Court, New Street, AYLESBURY, Buckinghamshire, HP20 2PB UK
- LinkedIn: www.linkedin.com/company/se-labs
7. Rapid7
Rapid7 is a cybersecurity company that works across different areas, from penetration testing to vulnerability management and threat detection. They’re not just about pointing out flaws but also about helping organizations figure out how to deal with them in a structured way. Their platform brings together tools for testing, monitoring, and incident response, so teams aren’t jumping between different systems to keep track of what’s going on.
Alongside the technology, Rapid7 also provides consulting and managed services. That means they can step in when a business doesn’t have enough in-house resources or just wants a second set of hands to guide the process. The mix of software and services is aimed at making security less overwhelming and giving companies a clearer picture of their actual risk.
Key Highlights:
- Global cybersecurity company with a UK presence
- Combines security testing, monitoring, and response tools
- Offers both software and hands-on consulting support
- Helps companies manage risks across infrastructure and applications
- Provides managed services for organizations needing extra support
Services:
- Penetration testing
- Vulnerability management
- Threat detection and response
- Incident response consulting
- Cloud and application security assessments
- Managed security services
Contact Info:
- Website: www.rapid7.com
- Phone: +44 (0)118 207 9300
- Address: 19 Chichester Street, Belfast, BT14JB, UK
- LinkedIn: www.linkedin.com/company/rapid7
- Twitter: x.com/Rapid7
- Facebook: www.facebook.com/rapid7
- Instagram: www.instagram.com/rapid7
8. Pentest People
Pentest People is a UK company that spends most of its time running penetration tests and helping organizations keep track of security gaps. Their focus is on making security testing part of day-to-day business rather than a once-a-year exercise. They’ve built their own platform to let clients see findings, track progress, and manage fixes over time, which makes the process feel more like ongoing maintenance than a single snapshot.
They also take on advisory work, so it’s not just about scanning and pointing out issues. They help companies figure out what those results actually mean in practice and how to prioritize what gets fixed first. It’s a mix of technical testing and practical guidance, aimed at making sure teams don’t get stuck with a long list of problems and no clear plan to handle them.
Key Highlights:
- UK-based penetration testing company
- Provides a platform for tracking security test results
- Focus on making testing a continuous process
- Works across networks, cloud, and applications
- Offers advisory support alongside technical tests
Services:
- Penetration testing
- Web application security testing
- Cloud security assessments
- Mobile app testing
- Infrastructure reviews
- Ongoing vulnerability management
Contact Info:
- Website: www.pentestpeople.com
- Email: info@pentestpeople.com
- Phone: 0330 311 0990
- Address: 20 Grosvenor Place, London, United Kingdom, SW1X 7HN
- LinkedIn: www.linkedin.com/company/pentestpeople
- Twitter: x.com/pentestpeople
- Facebook: www.facebook.com/pentestpeople
9. Renaissance
Renaissance is a UK company that works across different areas of IT security and risk management. They’re not just about selling tools but about putting together services that help organizations understand their risks and deal with them in a structured way. Their work ranges from protecting networks and data to helping companies prepare for compliance checks and industry standards.
They also act as a bridge between businesses and technology providers, bringing in the right mix of products and advice when needed. That might mean setting up managed security services, supporting with identity management, or helping teams plan how they’ll handle incidents. It’s a mix of technical expertise and practical guidance aimed at keeping day-to-day operations running without major security gaps.
Key Highlights:
- UK-based IT security and risk management company
- Works with businesses to handle compliance and governance needs
- Offers managed security alongside advisory services
- Focuses on both prevention and incident readiness
- Provides support across networks, cloud, and identity systems
Services:
- Managed security services
- Identity and access management
- Data protection and compliance support
- Incident response planning
- Network and cloud security solutions
- Security risk assessments
Contact Info:
- Website: www.renaissance.co.uk
- Email: web@renaissance.co.uk
- Phone: 01923690700
- Address: Unit 20, Orbital 25 Business Park Watford, WD18 9DA UK
- LinkedIn: www.linkedin.com/company/renaissance-computer-services
- Facebook: www.facebook.com/renaissancecomputers
10. LRQA
LRQA is a UK company that deals with assurance, inspection, and cybersecurity services. Their work is about helping organizations prove that their systems, processes, and security measures meet certain standards. That can cover everything from managing compliance frameworks to checking if security controls are actually doing the job they’re supposed to.
They also provide hands-on security testing and advisory work. This means they don’t just audit against a checklist but look at real-world risks across networks, applications, and supply chains. The mix of compliance and technical testing makes them a fit for companies that need both the paperwork and the practical side of security covered.
Key Highlights:
- UK-based provider of assurance and cybersecurity services
- Covers compliance, certification, and risk management
- Provides security testing alongside audits
- Works with organizations across different industries
- Focuses on both technical and governance aspects of security
Services:
- Cybersecurity audits and assessments
- Compliance and certification support
- Penetration testing
- Supply chain risk management
- Risk and governance advisory
- Security awareness and training
Contact Info:
- Website: www.lrqa.com
- Phone: +44 345 520 0085
- Address: 1,Trinity Park, Bickenhill Lane, Birmingham B37 7ES UK
- LinkedIn: www.linkedin.com/company/lrqa
- Twitter: x.com/lrqa
11. NCC Group
NCC Group is a UK-based cybersecurity company that works across a wide range of testing and advisory services. They’re known for getting into the details of systems, whether that’s running penetration tests, reviewing software, or checking supply chain risks. Their work isn’t just about finding weaknesses but also about helping businesses figure out how to handle them in a way that makes sense for their setup.
They also spend a lot of time on the bigger picture, like governance, compliance, and building long-term resilience. That means they’re not only looking at today’s problems but also at how companies can prepare for what’s coming next. It’s a mix of technical testing and practical advice, so organizations get both the detail and the strategy side of security.
Key Highlights:
- UK-based cybersecurity and risk management company
- Covers penetration testing, audits, and advisory services
- Looks at both technical details and governance frameworks
- Supports organizations with supply chain and compliance challenges
- Works across industries with tailored security approaches
Services:
- Penetration testing
- Security audits and risk assessments
- Software and cloud security reviews
- Compliance and governance support
- Supply chain risk management
- Incident response planning
Contact Info:
- Website: www.nccgroup.com
- Email: cirt@nccgroup.com
- Address: XYZ Building 2 Hardman Boulevard Spinningfields Manchester, M3 3AQ UK
- Phone: +4401612095200
- LinkedIn: www.linkedin.com/company/ncc-group
- Twitter: x.com/NCCGroupplc
12. Qualitest
Qualitest is a UK-based company that works mainly in software testing and quality assurance, but security testing is also a big part of what they do. Their approach is about making sure systems actually work the way they should, while also checking for vulnerabilities that could cause problems later. They step in across different industries, running tests on applications, infrastructure, and cloud environments to spot issues before they turn into real risks.
They also provide advisory support, so it’s not just about pointing out what’s broken. They help organizations figure out how to improve processes, strengthen security, and keep up with industry standards. It’s a mix of technical testing and practical advice that’s aimed at making day-to-day operations more reliable and less risky.
Key Highlights:
- UK-based software and security testing company
- Works across industries on applications, infrastructure, and cloud
- Focuses on both functionality and security of systems
- Offers advisory and process improvement alongside testing
- Supports compliance with industry standards
Services:
- Security testing
- Software quality assurance
- Cloud and infrastructure testing
- Application testing
- Risk and compliance support
- Advisory and process improvement
Contact Info:
- Website: www.qualitestgroup.com
- Address: Level 2, Equitable House 47 King William Street EC4R 9AF United Kingdom
- LinkedIn: www.linkedin.com/company/qualitest
- Twitter: x.com/QualiTest
- Facebook: www.facebook.com/Qualitestgroup
- Instagram: www.instagram.com/lifeatqualitest
13. Intruder
Intruder is a UK-based company that focuses on automated vulnerability scanning. The idea is to help organizations keep track of security issues without needing to run manual checks all the time. Their platform scans systems, flags weaknesses, and gives teams a way to stay on top of patches and fixes before attackers can take advantage.
They’re not trying to replace penetration testing altogether but to make the ongoing monitoring side easier. Instead of businesses finding out months later that something was left exposed, Intruder’s setup gives regular updates and alerts. It’s a straightforward approach that suits companies that want to manage risk in a more consistent and less reactive way.
Key Highlights:
- UK-based company focused on automated security scanning
- Provides continuous vulnerability monitoring
- Helps businesses stay ahead of patches and updates
- Designed to complement penetration testing, not replace it
- Aims to make day-to-day security more manageable
Services:
- Automated vulnerability scanning
- Continuous system monitoring
- Cloud and infrastructure checks
- Web application scanning
- Alerts and reporting for security issues
- Integration with existing workflows
Contact Info:
- Website: www.intruder.io
- Email: contact@intruder.io
- Address: Intruder Systems Ltd WeWork, 1 Mark Square, London, EC2A 4EG, UK
- LinkedIn: www.linkedin.com/company/intruder
- Twitter: x.com/intruder_io
- Facebook: www.facebook.com/intruder.io
14. GoAllSecure
GoAllSecure is a UK company that focuses on helping businesses identify and fix security gaps. A lot of their work involves penetration testing across different systems, from networks and cloud setups to web and mobile applications. The idea is to show companies where they’re exposed before someone with bad intentions finds the same holes.
They also provide consulting and advisory services, so it’s not just about testing once and leaving. They work with clients to build longer-term security strategies, covering things like risk management and compliance. It’s a mix of hands-on testing and practical guidance that gives businesses a clearer picture of their overall security position.
Key Highlights:
- UK-based cybersecurity company
- Focuses on penetration testing across systems and apps
- Works with both technical and compliance aspects of security
- Provides ongoing support, not just one-time testing
- Covers networks, cloud, web, and mobile environments
Services:
- Penetration testing
- Web and mobile application testing
- Cloud security assessments
- Infrastructure security reviews
- Risk management and compliance support
- Security consulting and advisory
Contact Info:
- Website: www.goallsecure.com
- Email: info@goallsecure.com
- Phone: +44 20 3287 4253
- Address: 2 Sail Court, 15 Newport Avenue, London E142DQ UK
- LinkedIn: www.linkedin.com/company/goallsecure
- Twitter: x.com/goallsecure
- Facebook: www.facebook.com/goallsecure
- Instagram: www.instagram.com/goallsecure
Conclusion
Security testing in the UK isn’t tied to one type of provider. You’ll find smaller teams that focus purely on penetration testing, as well as larger outfits that mix in compliance, advisory, and long-term monitoring. Some are more hands-on with day-to-day fixes, while others step back and help shape strategy.
The upside is choice. Whether a company wants regular scanning to stay on top of patches or a full red team exercise to stress-test their defences, there are firms here that can handle it. If you’re weighing options, starting with a straightforward assessment can be a good way to see how a partner works before committing to something bigger.
