We transform complex security challenges into actionable strategies that safeguard your organisation and drive operational excellence.
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Services

01

Governance, Risk and Compliance

Solution
As a leading cyber security consultant in London, we strengthen governance and risk programmes with clear, practical controls that improve maturity and help mitigate uncertainty across the organisation.
  • Framework gap analysis
  • Tailored risk assessments
  • Cyber security risk reporting
  • Ongoing compliance oversight
  • Policy and standard development
02

Compliance and Frameworks

Solution
We turn complex standards into simple, achievable actions. Our advisory services streamline certification journeys, sharpen documentation and guide you through efficient, low-friction compliance.
  • Remediation planning
  • Control design and mapping
  • ISO 27001 and SOC 2 support
  • Audit preparation and evidence
  • Continuous compliance monitoring
03

Vanta Implementation

Solution
We deliver smooth Vanta rollouts that automate compliance, reduce manual workload, and accelerate readiness for industry certifications with accurate control mapping and clean integrations.
  • SOC 2 / ISO 27001 preparation
  • Monitoring and alert tuning
  • Control mapping in platform
  • System and tool integrations
  • Vanta setup and configuration
04

vCISO and GRC Leadership

Solution
We provide strategic security leadership that drives clarity and direction. Our cyber security team supports governance, risk oversight, and long-term resilience planning across your organisation.
  • Policy governance
  • Incident advisory support
  • Security strategy roadmap
  • Board and executive reporting
  • Team coaching and mentoring
05

Penetration Testing

Solution
We identify real vulnerabilities through focused, methodical testing that mirrors attacker behaviour. Clear reporting and prioritised fixes ensure meaningful security improvements and stronger security measures.
  • Threat modelling
  • Web and API testing
  • Retesting for validation
  • Clear remediation reporting
  • Network and cloud assessments
06

Resilience and Recovery

Solution
We prepare organisations to withstand and recover from incidents through structured response planning, minimised downtime, and improved operational readiness across security and cloud environments, including AWS and Microsoft.
  • Tabletop exercises
  • Custom recovery runbooks
  • Post-incident improvements
  • Incident response planning
  • Continuity and recovery reviews

Built for Regulated Financial Institutions

Industry-leading cyber security consultancy services in London

Layered Scalable Security

Structured, multi-layered protection built to adapt as new cyber threats emerge. We strengthen resilience with a clear cyber security strategy shaped around your operations and long-term growth.

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Certified Expertise

CISSP-led security experts with two decades of experience delivering risk management, defence against cyber attacks & practical guidance across financial, trading, enterprise environments.

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Tailored Assistance

Detail-driven support from a trusted cyber security expert. We provide actionable, clear & practical guidance to keep your security improvements consistent, effective and aligned with your needs.

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London-Based & Remote

Flexible cyber security services delivered onsite in London for key engagements or remotely for fast and seamless ongoing support. Contact us for cyber security consulting solutions.

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Featured Case Studies

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Ninth Seat

“Onion Security worked alongside our existing IT supplier to provide an independent and constructive view of our security position. Their assessment helped us understand where we could strengthen our controls and prioritise future improvements. The guidance they provided was clear, practical and collaborative throughout. We now have a well-defined roadmap that supports our ongoing security strategy, and we are keen to work with them again to ensure we stay ahead of the ever-changing security threats."

Tim Gowing

Partner and Board Director
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FryerMiles

"Working with Onion Security has given us greater clarity and structure around how we protect candidate and client information. They made a real effort to understand the flow of data within our recruitment operations and offered guidance that suited the way our teams work. Their steady, knowledgeable support has strengthened our overall approach to security, and we value their ongoing role in helping us maintain strong and compliant practices."

Leo Miles

Founder and Director
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SportsFi

"Onion Security have been instrumental in guiding us through our ISO 27001 and SOC 2 journey. Their expertise, combined with effective tooling solutions, has helped us build clear and manageable compliance processes. We value the reassurance and support they provide at each stage, and they continue to play a key role in our ongoing security and compliance work."

Justin King

Founder & Co CEO
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Cunningham Eves Solicitors

"Onion Security supported our firm with clear, practical advice focused on safeguarding client confidentiality and meeting the expectations of our regulators. They quickly understood the nature of our legal work and provided guidance that fitted seamlessly with our existing processes. Their professionalism and measured approach have given us greater confidence in our security arrangements, and they remain a trusted resource for ongoing security and compliance matters."

Christine Eves

Senior Partner
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Construction Dynamics Solutions

“Onion Security invested the time to understand our firm, our workflows and the expectations of our clients. This allowed them to tailor their support precisely to our needs and provide guidance that was both practical and proportionate. Their work has helped us strengthen our security posture and gain clearer oversight of our compliance obligations. We value their measured, professional approach and are pleased to have them as our trusted security and compliance partner.”

Sam Mattar

Founding Partner
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Codertonic

"Onion Security provides expert support across our security and compliance needs, including thorough penetration testing that offers valuable insight and assurance. Their advice is clear, reliable and aligned with the way we work, which strengthens our approach without disrupting our development process. They have become a trusted partner for security matters, and I would not hesitate to recommend them."

Chris Hoyes

CEO/CTO and Co-founder
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Cyber Security Solutions

Delivering a robust cyber security posture that withstands any threat