Penetration Testing London
Precursor Security provides CREST-accredited penetration testing in London through our London office, backed by our full UK testing team. We deliver web application, API, infrastructure, cloud, and red team engagements for London financial services firms, SaaS companies, and legal practices, with on-site testing across Greater London and scoping calls typically within 24 hours.
CREST-accredited penetration testing for London organisations: web applications, APIs, infrastructure, cloud, and red team operations. Delivered through our London office with the depth of our full UK testing team behind it, and on-site coverage across Greater London.
Testing calibrated for London's
regulatory density.
London concentrates more regulated organisations than anywhere else in Europe: FCA-supervised financial services, DORA-scoped firms, international law practices, and a SaaS ecosystem selling into all of them. Testing here is rarely just technical; it feeds audits, client due diligence questionnaires, and regulatory evidence packs. Our London engagements are built for that reality, with CREST-accredited methodology, reports written for both engineers and auditors, and retesting included so remediation evidence is ready before your next review.
Who We Test In London
Testing scoped to the sectors that define London's economy, because a meaningful penetration test starts from who actually attacks businesses like yours, and what they are after.
How We Reach You
London is served from our London office. Our London office supports capital-based clients, backed by the Leeds testing team two hours away by rail.
CREST-Accredited, Verifiably
Precursor Security holds CREST organisational accreditation for penetration testing, independently audited across methodology, QA, and tester competency. Every engagement letter carries our membership number for direct verification by your auditors, insurers, or customers.
No Travel Games. No Scanner Reports. No Offshoring.
London clients get the same team, methodology, and day rate as our London and Leeds clients: manual testing by employed, UK-based CREST Registered Testers, fixed quotes agreed at scoping, immediate escalation of critical findings, and free retesting of everything you fix. On-site internal, wireless, and physical testing across Greater London, coordinated through our London office.
Every Test,
Delivered In London.
The full offensive security portfolio is available to London organisations. Each service links to its full methodology, and every engagement ends with reporting your engineers can action and your auditors can file.
Web Application Penetration Testing London
Manual, CREST-accredited testing of the web applications and APIs your London business depends on. Full OWASP coverage plus the business logic and access control flaws automated scanners miss, with free retesting of every finding.
Internal & External Network Testing London
External testing of your internet-facing perimeter, and internal testing that maps what an attacker could reach once inside: Active Directory attack paths, lateral movement, and privilege escalation. On-site delivery in London.
Cloud Penetration Testing London
Configuration review and attack-path testing across AWS, Azure, Microsoft 365, and GCP. We find the identity misconfigurations, exposed storage, and over-privileged roles that cause most real cloud breaches.
Wireless Network Testing London
On-site assessment of your wireless estate in London: rogue access point detection, segregation between guest and corporate networks, and attacks against enterprise authentication.
Mobile Application Testing London
iOS and Android application assessments covering insecure storage, API trust boundaries, and platform hardening, for London businesses shipping mobile products or internal apps.
Cyber Essentials & Compliance London
Cyber Essentials and Cyber Essentials Plus certification, ISO 27001 support, and PCI DSS testing for London organisations that need recognised certification alongside technical assurance.
Threat Detection & Response for London, 24/7.
A penetration test proves what an attacker could do today. Our UK Security Operations Centre watches for the ones who try tomorrow: managed detection and response, a CREST-accredited SOC, and incident response for London organisations, delivered entirely from UK soil.
Explore Defensive SecurityHow Engagements Run In London.
From first call to free retest. Every London engagement is managed by a named account manager with direct access to the testing team, no ticket queues between you and the people doing the work.
Scoping & Fixed Quote
A free scoping call, usually within 24 hours of your enquiry, where a technical consultant (not a salesperson) defines what needs testing, agrees the approach, and produces a fixed quote. London clients can scope by video call or, where practical, in person via our London office.
Testing In London
CREST Registered Testers execute the engagement during agreed windows: remote phases for external, web, and cloud testing, and on-site or appliance-based delivery for internal and wireless work in London. You get daily progress updates, and critical findings are escalated immediately rather than saved for the report.
Reporting Built for Two Audiences
Every report contains an executive summary your board and customers can read, and a technical annex your engineers can action: reproduction steps, evidence, CVSS scoring, and specific remediation guidance. Reports are quality-assured before delivery and structured for auditors, insurers, and customer due diligence reviews.
Debrief & Free Retesting
A full debrief walks your team through findings and attack chains, in person in London or at our London office where practical, or by video call. Once you have remediated, we retest the fixed findings free of charge and issue updated reporting, so your evidence shows issues closed, not just found.
The best time to test your defences is now.
Join the high-growth companies relying on Precursor for continuous offensive and defensive security.
Frequently Asked Questions
Common questions about this service, methodologies, and deliverables.
Penetration testing for London organisations typically costs between £2,500 and £25,000 plus VAT depending on scope. A focused single web application or external infrastructure test usually falls between £2,500 and £6,250, most standard engagements land between £3,750 and £12,500, and larger multi-scope programmes range higher. Location does not change our day rate: London clients pay the same as London clients. Every quote is fixed after a free scoping call, and retesting of fixed findings is included.
London is served from our London office. Our London office supports capital-based clients, backed by the Leeds testing team two hours away by rail. On-site internal, wireless, and physical testing across Greater London, coordinated through our London office. All testing is delivered by UK-based, employed testers, never subcontracted or offshored.
FCA-regulated firms are generally expected to use recognised, accredited testing providers, and CREST accreditation is the most widely accepted UK benchmark. Precursor Security holds CREST organisational accreditation for penetration testing, delivers threat-led engagements aligned to regulatory expectations, and provides reporting suitable for FCA, DORA, and client due diligence evidence.
Yes. A large share of our London work is penetration testing that feeds SOC 2 audits, ISO 27001 certification, and enterprise procurement security questionnaires. We provide letters of attestation, executive summaries safe to share with prospects, and retesting so your remediation evidence is complete before the audit or deal closes.
Yes. Precursor Security holds CREST organisational accreditation for penetration testing, the leading UK standard for testing providers, alongside ISO 27001:2022 certification and Cyber Essentials Plus. Testing in London is delivered by CREST Registered Testers with additional certifications including OSCP, and our engagement letters reference our CREST membership number so auditors, insurers, and customers can verify it directly.