Top 10 in Tech: London's most valuable Security startups

Josh Peachey's picture
by Josh Peachey

Continuing our Top 10 tech series of London’s most valuable startups, this week, we’re looking at the world of security and seeing which London-born startups are valued highly because of their ability to keep data safe. 

In such an online world, individuals, organisations and companies are always facing security threats. The rise in widespread tech usage has brought with it a rise in online security solutions to help keep private information out of the wrong hands. 

Utilising Tech Nation's Data Commons service, Prolific London has taken a look at the most valuable London-based startups focused on security - including apps, tools, SaaS companies and AI-driven solutions. This listing is based on valuations of companies at time of writing.

Let's see who made it into the Top 10...

1. Netsparker

Netsparker is a scalable, multi-user web application security solution with built-in workflow and reporting tools ideal for security teams. It’s available as a hosted and self-hosted solution and can be fully integrated into any development or testing environment. 

The company uses its proprietary Proof-Based-Scanning technology to automatically verify false positives and save users considerable time.  

Founded: 2009
Value: £230 million - £330 million

2. Tessian

Tessian is an email security platform that prevents spear phishing, accidental data loss and non-compliant activity caused by human failure on email. Companies using Tessian include Investec, rightmove, Schroders, Vernalis and more. 

Tessian’s Human Layer Security (HLS) platform uses stateful machine learning to analyze inbound and outbound emails in order to automatically prevent cybersecurity threats.

Founded: 2013
Value: £131 million - £200 million

3. Privitar 

Used by BT, HSBC, NHS Digital and others, Privitar creates software designed for enterprise-wide privacy protection. Privitar Publisher is a comprehensive solution for data privacy protection and governance whilst Privitar Lens provides a straightforward way to create commercial data products that safely monetise sensitive data. Privitar FastStart is specifically designed for startups and includes support and training.

Founded: 2014
Value: £131 million - £200 million

4. Callsign

Callsign specialises in realtime authentication solutions that confirm the user really is who they say they are, at work and at home. Through the use of AI, Callsign provides risk intelligence in real time, enabling organizations to intelligently adjust authentication journeys. 

Their products use deep learning techniques to combine event, threat, and behavioural analytics with multi-factor authentication, securing access to services whilst uniquely ensuring the most frictionless and transparent user experience.

Founded: 2011
Value: £115 million - £170 million

5. ComplyAdvantage

ComplyAdvantage’s mission is to solve financial crime. The founder, Charles Delingpole, created the solution so that compliance professionals, who are trying to reduce financial crime, and more importantly, the nefarious activity it facilitates, weren’t hindered by ‘false-positives’. ComplyAdvantage has partnered up with regulators around the globe. 

Founded: 2014
Value: £100 million - £150 million


6. Garrison Technology

Garrison looks to protect employees from clicking on risky links and therefore protect companies from targeted software attacks, using tools such as ‘Ultra Secure Browsing’. They also use hardware solutions - the Garrison Savi - to support their secure remote browsing solution. 

Their technology goes further than just protecting against dodgy links, it ensures copied and pasted content is safe to use by converting them to an acceptable format. 

Founded: 2014
Value: £100 million - £150 million

7. Snyk

Open source code is a serious boost to productivity but taking code written by others, often with little to no vetting of its security pedigree, can put your application at risk. Over 300,000 developers use Snyk to find, and more importantly fix known vulnerabilities in open source. 

Companies like Skyscanner, Google, Microsoft and The Guardian all make use of Snyk.

Founded: 2015
Value: £82 million

8. Yoti 

Yoti believes that everyone, no matter who they are or where they’re from, deserves a simple and secure way of proving their identity. Their secure digital identity app lets individuals share only the details they choose to, without revealing their whole identity. 

Personal details are encrypted into unreadable data that can only be unlocked by the users’ own Yoti app. Nobody else can access or decipher it.

Founded: 2014
Value: £81 million


Over 600 brands rely on Incopro to protect their online brand and intellectual property, including Nurofen, Veet, Lindt, Detol, ghd, Cadbury and more. 

Counterfeiters are constantly finding innovative new ways to infringe on legitimate businesses and Incopro regularly update their anti-counterfeiting products to enable brands to stay ahead of the fakers. 

Founded: 2012
Value: £69 million - £103 million

10. Ravelin

Ravelin provides sophisticated technology and dedicated support to help you prevent evolving fraud threats and accept payments with confidence. Machine Learning, graph networks, and a full-featured rules engine provide the technical underpinning to the company’s fraud strategy. 

Founded: 2014
Value: £32m - £48m