20 Best London Cybersecurity Companies

In the bustling heart of London, cyber threats silently stalk the digital alleyways. This lurking danger often catches businesses off guard, leaving them exposed in this rapidly evolving IT Security London landscape. The importance of comprehensive endpoint security and active intrusion detection is like the whispering wind – it’s always there, but we often fail to hear it.

Too many firms find themselves scrambling, trying to keep pace with the advancing digital threats. Despite maintaining basic firewall protection, they grapple with advanced cyber risks. The struggle is real, and the vulnerability is palpable.

Here’s where the heralded London cybersecurity firms enter the fray with their high-caliber, all-encompassing cybersecurity solutions. These titans in the cyber realm offer a spectrum of services, standing as bulwarks against digital invasion. Stick with us as we unravel the top 20 cybersecurity companies in London – your vanguards in the complex world of cybersecurity. It’s time to navigate these intricate waters together.

1. A-Listware

At A-listware, we provide cybersecurity solutions that help organizations reduce risk, maintain compliance, and stay resilient against modern cyber threats. With delivery hubs in Ukraine, Poland, and Romania, and offices in the UK and USA, we support clients across finance, healthcare, retail, telecommunications, and manufacturing.

Our services include infrastructure and application security testing, vulnerability management, cloud and web application protection, mobile device management, SIEM deployment and tuning, DDoS mitigation, and compliance assistance for ISO 27001, SOC 2, HIPAA, and GDPR.

Unser Team consists of certified ethical hackers, DevSecOps engineers, SIEM specialists, and compliance consultants. We work through structured assessments, risk analysis, and tailored remediation plans that align security improvements with business needs.

Some of our recent projects demonstrate our experience across high-risk and regulated industries. For a financial institution, we conducted a full-scale penetration test targeting their online banking platform, identifying and addressing critical vulnerabilities. In the healthcare sector, we supported a regional provider through a successful HIPAA audit by implementing robust data protection measures for sensitive patient information. For an e-commerce platform experiencing repeated DDoS attacks, we restored full operations within hours and deployed a long-term mitigation strategy to prevent future disruptions

Kontakt today to learn how we can help secure your business in an evolving threat landscape.

• Headquarters: London, UK
• Founded: 2017
• Specialization: Cybersecurity and Compliance Services for Regulated and Digital-Facing Industries

2. ReliaQuest

ReliaQuest is a London-based cybersecurity company that provides cyber situational awareness to help organizations protect against cyber threats. The company’s SearchLight service offers a comprehensive view of an organization’s digital footprint and the profile of its potential attackers. This service continuously monitors for digital risks beyond the boundary of an organization, identifying cyber threats, data leakage, and reputational risks. ReliaQuest provides actionable threat intelligence, context, remediation options, and automated takedown capabilities to enable organizations to minimize risks and respond effectively to threats.

• Headquarters: London, United Kingdom
• Founded: 2019
• Specialization: Cyber Situational Awareness

3. Tessian

Tessian is a cybersecurity company based in London that has developed a machine-intelligent email security platform to automatically prevent security threats. These threats include misaddressed emails, data loss, and non-compliance. Tessian’s platform uses machine learning to understand normal email communication patterns and behaviors. This enables it to automatically identify email security threats in real time, eliminating the need for human review or manual intervention. The company’s mission is to secure the human layer of organizations by protecting individual employees from inbound threats and preventing data exfiltration.

• Headquarters: London, United Kingdom
• Founded: 2013
• Specialization: Email Security

4. Deep Secure

Deep Secure, headquartered in London, provides innovative cybersecurity solutions designed to protect against content threats. The company’s threat removal platform offers a unique, transformational approach to cybersecurity. Instead of trying to identify and block threats, Deep Secure’s technology transforms the content, ensuring that any hidden threats are removed while preserving the business value of the data. This approach provides a level of security that goes beyond traditional threat detection and offers a way to achieve zero-trust content security.

• Headquarters: London, United Kingdom
• Founded: 2010
• Specialization: Content Threat Removal

5. CyberSmart

CyberSmart is a London-based cybersecurity company that offers a platform designed to automate implementation, certification, and compliance with cybersecurity standards. The platform continuously identifies security weaknesses, provides guidance on how to fix them, and documents everything for compliance purposes. CyberSmart’s approach simplifies the process of achieving and maintaining compliance with standards such as Cyber Essentials and ISO 27001, making it easier for organizations to protect their data and demonstrate their commitment to cybersecurity.

• Headquarters: London, United Kingdom
• Founded: 2016
• Specialization: Cybersecurity Compliance

6. Panaseer

Panaseer is a cybersecurity company based in London that provides continuous control monitoring to businesses. The platform gives businesses a comprehensive view of their assets and shows how well they’re being protected. Panaseer’s platform uses automated data processing and an advanced analytics engine to provide insights into the security status of an organization’s IT assets. This enables organizations to identify gaps in their security controls and take proactive steps to improve their cybersecurity posture.

• Headquarters: London, United Kingdom
• Founded: 2014
• Specialization: Continuous Controls Monitoring

7. Glasswall

Glasswall is a cybersecurity company that provides organizations with unique protection against file-based threats. Many of the world’s leading organizations trust Glasswall’s patented deep-file inspection, remediation, sanitization, and document reconstruction products. The company’s innovative approach ensures safe, visually identical files while ensuring all threats are eliminated.

• Headquarters: London, United Kingdom
• Founded: 2005
• Specialization: File-based Threat Protection

8. SenseOn

SenseOn offers a unique and innovative AI platform for cyber defense. The SenseOn platform provides organizations with a unique way of detecting threats across their digital estate. By understanding the ‘normal’ behavior of each user and device, SenseOn can spot subtle deviations indicative of a threat, even in the noise of a busy network.

• Headquarters: London, United Kingdom
• Founded: 2017
• Specialization: AI Cyber Defense

9. Featurespace

Featurespace is a world leader in risk prevention and fraud detection. The company’s adaptive behavioral analytics technology uses machine learning to understand the behavior of each individual within a network, enabling organizations to detect and prevent fraud in real time.

• Headquarters: London, United Kingdom
• Founded: 2008
• Specialization: Fraud Detection and Risk Prevention

10. Callsign

Callsign is a cybersecurity company that provides AI-driven intelligence-driven authentication solutions. The company’s Intelligence Driven Authentication (IDA) solution enables businesses to deliver seamless and secure customer experiences across multiple channels.

• Headquarters: London, United Kingdom
• Founded: 2012
• Specialization: Intelligence-Driven Authentication

11. Darktrace

Darktrace is a leading autonomous cyber defense platform that uses AI to self-learn and self-defend networks. Over 3,000 organizations utilize the company’s technology, which is modeled after the human immune system, to guard against attacks to the cloud, email, IoT, networks, and industrial systems.

• Headquarters: London, United Kingdom
• Founded: 2013
• Specialization: Autonomous Cyber Defense

12. BullGuard

BullGuard is a London-based cybersecurity company that provides robust, layered protection against all types of malware, such as phishing attempts and trojans. BullGuard’s award-winning security suite includes a range of features, including a custom-built secure browser, a home network scanner, and a powerful game booster to optimize CPU performance.

• Headquarters: London, United Kingdom
• Founded: 2002
• Specialization: Internet Security

13. BeyondTrust

BeyondTrust, formerly known as Avecto, is a cybersecurity software company that believes security can be synonymous with user freedom. BeyondTrust’s Defendpoint software elegantly combines the three core pillars of cybersecurity: privilege management, application control, and content isolation, providing a proactive, pragmatic approach to security.

• Headquarters: London, United Kingdom
• Founded: 2008
• Specialization: Cybersecurity Software

14. Egress

Egress Software Technologies is a forward-thinking cloud-based software security company. Egress assists businesses in protecting unstructured data in order to satisfy legal requirements and increase corporate efficiency. The AI-powered platform of the firm analyses and reports on user behavior, avoiding human-activated data breaches before they occur.

• Headquarters: London, United Kingdom
• Founded: 2007
• Specialization: Cloud-based Software Security

15. Clearswift

Clearswift is a cybersecurity company that provides advanced threat protection and enterprise-grade security. Clearswift’s products are designed to prevent data loss, manage insider threats, guard against ransomware, and protect against other cyber threats. Thousands of organizations worldwide rely on them to protect their important information, allowing them to safely communicate and promote business success.

• Headquarters: London, United Kingdom
• Founded: 1982
• Specialization: Advanced Threat Protection

16. Cylon

Cylon operates as a cybersecurity accelerator that supports early-stage startups in the cybersecurity field. The company provides startups with the tools and support they need to grow and succeed. This includes everything from capital to coaching and a network of influential contacts. Cylon’s unique approach to cybersecurity makes it a key player in the London cybersecurity scene.

• Headquarters: London, United Kingdom
• Founded: 2015
• Specialization: Cybersecurity Accelerator

17. iProov

iProov is a world leader in spoof-resistant, biometric facial verification. The company’s technology ensures that an online user is the right person, a real person, and is authenticating right now. This defends against identity theft and unauthorized access, providing a secure and effortless user experience.

• Headquarters: London, United Kingdom
• Founded: 2011
• Specialization: Biometric Facial Verification

18. CyberOwl

CyberOwl provides an early-warning system for cyber-physical attacks. The company’s technology uses a probabilistic framework to systematically aggregate weak indicators of an attack to provide a risk-prioritized view. This allows for more timely and contextualized decision-making.

• Headquarters: London, United Kingdom
• Founded: 2016
• Specialization: Early Warning System for Cyber-Physical Attacks

19. Salt Security

Salt Security safeguards APIs, which are at the heart of every SaaS, online, mobile, microservices, and IoT application. The API Protection Platform from the firm is the industry’s first patented solution for preventing the next generation of API assaults through behavioral protection. Salt Security was created by former members of Israel’s top cybersecurity team.

• Headquarters: London, United Kingdom
• Founded: 2016
• Specialization: API Protection

20. TechQuarters

TechQuarters is a London-based IT support and consulting company that specializes in leveraging Microsoft cloud solutions to enhance business operations. The firm provides various cybersecurity services, including managed IT services, professional IT services, Microsoft Azure hosting, IT training, and IT security. TechQuarters prides itself on its ability to help businesses save money and derive more benefits from technology. Their strategy is not limited to mending things when they fail; they also focus on monitoring your infrastructure and putting technologies in place to reduce occurrences of system problems. Their goal is to prevent all preventable errors, and in the odd event that an unavoidable fault occurs, measures will be in place to minimize the impact on your organization.

• Headquarters: London, United Kingdom
• Founded: 2007
• Specialization: IT Support and Consulting, Microsoft Cloud Solutions

Schlussfolgerung

Arming yourself with the right cybersecurity firm is an imperative move in today’s digital landscape. This list of the 20 best cybersecurity firms in London represents the crème de la crème in the industry, each providing robust, comprehensive solutions tailored to meet unique challenges. They are the frontline defense against cyber threats, promising to secure your digital world. Use this list as your go-to reference for making well-informed choices that will strengthen your cyber defenses. With London’s cybersecurity experts, you can take your cybersecurity to the next level.