Security startups in the United Kingdom

Universal artifact control plane for what AI and humans actually put into production.

Raised $72M Series C led by TCV and Insight Partners, April 2026

Security and governance platform that discovers the AI agents running across an enterprise, records how they behave, scores their risk and constrains them at runtime.

Raised a $30M Series A led by Balderton Capital, May 2026

AI agents that investigate cloud and code vulnerabilities, reproduce attacker steps to confirm which are exploitable, and drive the fixes for security teams.

Raised a $25M Series A led by Theory Ventures, June 2025

Attacker-style recon and automated red team for models, agents, IDEs, and the systems around them.

Raised $30M Series A led by Album VC, August 2026

Email authentication and brand protection that gets domains to DMARC enforcement without a DNS circus.

Won a 2025 Cybersecurity Excellence Award for OnDMARC, March 2025

Supplier security as a shared network: each supplier keeps one security profile that every connected customer can see, instead of answering questionnaires one by one.

Raised a GBP 24M Series B led by Axiom Equity, July 2026

Agentic security platform that reads code, infrastructure, configurations and AI agents together, prioritizes real attack chains, and verifies each fix, for teams shipping agents quickly.

Came out of stealth with a $13M seed round led by LocalGlobe and Cambridge Innovation Capital, April 2026

Control architecture that runs sensitive AI and high-consequence workloads in customer-controlled, compartmentalised environments, including on hyperscaler clouds.

Raised a $50M Series A led by New Enterprise Associates, July 2026