Cybersecurity by design
BUILD YOUR
MATURE STRONG LASTING
SECURITY POSTURE WITH US
CERTIFIED PCI DSS QSA Company
Highly experienced and qualified team ready to serve your needs
London, United Kingdom 
+44 2070728803 
LOCKED STACK EXPERTS IN IDENTIFYING
REQUIREMENTS AND SOLUTIONS IN
ABOUT US
Locked Stack is an independent cybersecurity consultancy and managed services firm with headquarters in London, United Kingdom, and Dover, Delaware, operating across North America, Europe, and the UK.
We specialise in payment security and broader risk management, delivering structured advisory and managed services that support regulatory and industry standards across both business and technology environments. Our capabilities span PCI DSS, PCI 3DS, ISO/IEC 27001/2, GDPR, DORA, GLBA, NIST, HIPAA, and the UK Data Protection Act.
Payment card security is central to Locked Stack’s offering. Our team has practical, end-to-end experience across the payments landscape, working with issuers, acquirers, card networks, and third-party service providers.
We work with organisations ranging from growing enterprises to public sector bodies, providing repeatable and sustainable compliance programs designed to deliver measurable value over time. Our technology-assisted approach reduces assessment effort, shortens compliance timelines, and supports ongoing regulatory alignment.
Our consultants bring extensive real-world experience in security assurance, risk, and regulatory delivery, with prior roles in global enterprise environments. This depth of experience allows us to address complex security and compliance challenges with confidence and scale.
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Clive Boonzaaier
Co-Founder & COO
Clive has over twenty years of experience in cybersecurity and regulatory compliance.
Clive is a PCI DSS Qualified Security Assessor (QSA) and PCI Professional (PCIP – Payment Card Industry Professional), with extensive experience supporting PCI DSS compliance programmes, including 3-D Secure (3DS) environments. He is also an ISO/IEC 27001 Lead Auditor, Certified Information Security Manager (CISM), and CISMP certified. In addition, Clive has significant experience working with regulatory frameworks such as HIPAA, the Gramm–Leach–Bliley Act (GLBA), and the General Data Protection Regulation (GDPR) across regulated industries. -
Martyn Martynowicz
CEO, Co-Founder
Martyn has more than two decades of experience in the IT and information security sector.
Martyn is an ISO/IEC 27001 Lead Auditor and Lead Implementer and holds the qualification of PCI Professional (PCIP – Payment Card Industry Professional). He has extensive experience working with PCI DSS and NIST-aligned security frameworks and a strong background in developing and overseeing security programmes that protect the confidentiality, integrity, and availability of business-critical information. -
Mark Daeche
Co-Founder & COB
Mark is a software engineer by training with decades long experience in sofware field.
Mark held senior management and executive roles within the global PC software industry across the United States and Europe. His career spans large-scale corporate environments as well as entrepreneurial ventures in technology-driven markets. -
Celeste Roux
Director of Operations
Celeste has a professional background in operations, marketing, and sales, with formal experience in customer service management and commercial operations across multiple industries.
Celeste expertise spans operational oversight, customer engagement, and marketing support, enabling effective alignment between service delivery, sales functions, and organisational objectives. -
Fiona Howard
Fiona holds a Master’s degree in Information Security and is a PCI DSS Qualified Security Assessor (QSA), as well as an ISO/IEC 27001 Lead Auditor and Lead Implementer.
Fiona professional experience spans a range of IT and security environments, with a particular focus on PCI DSS certification and information security assurance.
KNOWLEDGE
Let Locked Stack™ help you choose the right cyber security programme and supporting framework for your business and walk you through the implementation process and certification.
The advance of technology is based on making it fit so that you don't really even notice it, so it's part of everyday life.
-Bill Gates
GET IN TOUCH WITH OUR TEAM
Get in touch with our team to discuss your cybersecurity, compliance, and governance requirements, or to understand how our services can support your organisation’s security and risk objectives. We work with organisations operating in complex and regulated environments and provide clear, practical guidance aligned to business and regulatory expectations.
Need specific help?
Our team is ready to guide you through every step, offering clear support whenever you need it most.