Top 100 Penetration Testing Companies in London
The Best of December 2025Looking for a top penetration testing company in London?
Having vulnerable security poses a threat to your organization. In an age where data has become some of the most important assets that your company will have, improving security measures is always a must. Penetration testing aims to solve this problem by simulating real-life security breaches without the risk of an actual cyberattack. Also known as ethical hacking, this process helps identify weak spots within your IT network infrastructure by applying methods that real attackers would use.
A penetration testing company can assist you in determining your security vulnerabilities. Doing so will provide you with the information that you need to fortify your cybersecurity. Hiring the right penetration testing company can give you a significant advantage in safekeeping your virtual assets.
To assist you in your search for a partner, we’ve compiled this list of the top penetration testing services in London. Browse descriptions, feedback, and awards to find which can best suit your company’s needs.
List of the Best London Penetration Testing Services
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1$25,000+1,000 - 9,999 employeesLondon, EnglandRead More
ELEKS is a custom software development firm established in 1991. Their large team is in Tallinn, Estonia; L'viv, Ukraine; Berlin, Germany and Rzeszów, Poland. Their services include Custom Software Development, BI & big data consulting & SI, cloud consulting & SI, Cybersecurity, and more.
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BNY Mellon DPD Acino DRAXIndustries
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2$5,000+1,000 - 9,999 employeesBelrose, AustraliaRead More
ERRNA is a blockchain company founded in 2015. The small San Jose, California-based team provides blockchain, cybersecurity, marketing strategy, mobile app development, and more.
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3$5,000+50 - 249 employeesLondon, EnglandLocated in London, England and Düsseldorf, Germany, Transputec Ltd is a Cybersecurity company. The midsize agency was launched in 1986. Their services include Cybersecurity, IT managed services, Artificial Intelligence, cloud consulting & SI, and more.Read More
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4$5,000+10 - 49 employeesLondon, EnglandLaunched in 2012, Texaport is an IT managed services company. The small team provides IT managed services, Cybersecurity, cloud consulting & SI, IT strategy consulting, and more. The firm is headquartered in Edinburgh, Scotland; Glasgow, Scotland; London, England and Manchester, England.Read More
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5Undisclosed50 - 249 employeesLondon, EnglandBreachLock Inc is an Application Testing company. Launched in 2019, the midsize agency is based in New York, New York; Amsterdam, Netherlands and London, England. Their team offers Application Testing, Cybersecurity, and DevOps Managed Services.Read More
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6$1,000+10 - 49 employeesLondon, EnglandStingrai Inc. Is a Toronto, Canada-based Cybersecurity company. The small firm was founded in 2021. Their team offers Cybersecurity.Read More
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ClicktransIndustries
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7$10,000+250 - 999 employeesLondon, EnglandRead More
A1QA logo is a quality assurance and software testing company founded in 2002. Based in Denver, they have a team of 200+ employees that specialize in application testing and cybersecurity. They primarily serve midmarket clients in the IT and telecommunications industries.
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AdidasIndustries
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8$10,000+250 - 999 employeesGdynia, PolandRead More
Link Group Global, inc. Is an Austin, Texas-based human resources agency. The midsize company was established in 2015. Their services include HR services, IT managed services, and IT staff augmentation.
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DanoneIndustries
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9Undisclosed50 - 249 employeesLondon, EnglandRead More
Sagiton is a business-oriented software house located in Wroclaw, Poland. The company was founded in 2010 and now employs a team of 48 people. Sagiton provides custom software development, cybersecurity, mobile app development, IT strategy consulting, marketing strategy, and web design services. Most of their clients are small businesses.
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TapWinWinIndustries
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10$1,000+10 - 49 employeesLondon, EnglandRead More
Smartdesc is a London-based IT company with a team of fewer than 50 people. Founded in 2011, they offer IT strategy consulting, cloud consulting, and cybersecurity solutions for small and mid-market businesses, primarily non-profit organizations.
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MindIndustries
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11$5,000+10 - 49 employeesTower Bridge Rd, EnglandClear Thinking IT Solutions is an IT managed services company. Launched in 2009, the small firm is headquartered in Billericay, England; Tower Bridge Rd, England; Basildon, England and City of London, England. Their team focuses on IT managed services, Cybersecurity, and IT strategy consulting.Read More
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12$1,000+10 - 49 employeesLondon, EnglandTWC IT Solutions is an IT managed services company in London, England; Jersey City, New Jersey and Central, Hong Kong. The small team offers IT managed services, IT strategy consulting, cloud consulting & SI, unified communications consulting & SI, and more and was launched in 2011.Read More
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13$25,000+10,000+ employeesParis, FrancePersistent Systems is a data analytics company. Established in 1990, the large agency is headquartered in Pune, India; Santa Clara, California; Paris, France and Lyne, England. Their services include BI & big data consulting & SI, cloud consulting & SI, Cybersecurity, Custom Software Development, and more.Read More
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14$1,000+10 - 49 employeesLondon, EnglandRead More
Teceze Ltd is a London-based IT company founded in 2012 with more than 10 employees. They are experts in IT strategy consulting, cybersecurity, and IT managed services for clients that work in the industries of business services, consumer products, and more.
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Outsell, Inc.Industries
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15$250,000+2 - 9 employeesLondon, EnglandSanRa is a Cybersecurity company established in 2022. The small team specializes in Cybersecurity.Read More
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16Undisclosed250 - 999 employeesLondon, EnglandProfessional Advantage is a midsize ERP consulting and SI company in North Sydney, Australia and Melbourne, Australia. Their services include ERP consulting and SI and cloud consulting & SI.Read More
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17Undisclosed250 - 999 employeesKent, EnglandAir IT is an IT strategy consulting company established in 2005. Based in Sandiacre, England and Birmingham, England, the team specializes in IT strategy consulting and cloud consulting & SI.Read More
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18$1,000+2 - 9 employeesLondon, EnglandHeadquartered in London, England, Cynance is a Cybersecurity company. Established in 2019, the team specializes in Cybersecurity.Read More
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19$25,000+1,000 - 9,999 employeesLondon, EnglandNetsol Technologies Inc. Is a Cybersecurity company. Based in Los Angeles, California and London, England, the team specializes in Cybersecurity and cloud consulting & SI.Read More
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20$1,000+50 - 249 employeesLondon, EnglandMidsize Cybersecurity company Clear Infosec, is based in Jersey City, New Jersey and Toronto, Canada. The team focuses on Cybersecurity and IT strategy consulting.Read More
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21$5,000+10 - 49 employeesLondon, EnglandCovertSwarm is a Cybersecurity company. Based in London, England and Wilmington, Delaware, their team offers Cybersecurity.Read More
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22Undisclosed250 - 999 employeesLondon, EnglandLittlefish Managed IT Services is an IT managed services company. Their midsize team is located in Nottingham, United Kingdom; Sheffield, United Kingdom and London, United Kingdom. The firm specializes in IT managed services, cybersecurity, cloud consulting & SI, and IT strategy consulting. The firm was established in 2003.Read More
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23Undisclosed250 - 999 employeesLake Oswego, ORFounded in 1986, Online Business Systems is a Cybersecurity company. The team specializes in Cybersecurity and IT strategy consulting.Read More
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24$10,000+50 - 249 employeesStanmore, EnglandMicromindercs is a Cybersecurity company. Launched in 2018, the team focuses on Cybersecurity and IT managed services.Read More
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25Undisclosed10 - 49 employeesLondon, EnglandLaunched in 2017, Hazy is a small big data company. Their services include BI & big data consulting & SI and Artificial Intelligence.Read More
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26Undisclosed50 - 249 employeesLondon , EnglandPenguin Commercial Limited, a Corporate Travel Management company, is located in London , England. The team focuses on Corporate Travel Management and IT managed services.Read More
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27$1,000+10 - 49 employeesLondon, EnglandSectricity is a Cybersecurity company established in 2021. In Merelbeke-Melle, Belgium and London, England, the team specializes in Cybersecurity.Read More
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28Undisclosed250 - 999 employeesLondon, EnglandRedscan is a Cybersecurity company founded in 2015. Their team offers Cybersecurity.Read More
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29Undisclosed2 - 9 employeesCity of London, EnglandCyPro, a Cybersecurity company, was established in 2021. Headquartered in City of London, England, the team focuses on Cybersecurity.Read More
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30Undisclosed2 - 9 employeesLondon, EnglandHookPhish is a Cybersecurity company. They are in London, England, and their services include Cybersecurity.Read More
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