Trustgent
Application security · United Kingdom

Verified Application security companies in United Kingdom.

Every AI builder headquartered in United Kingdom with a verified Application security delivery record at Trustgent — cross-referenced (L2) or higher. Ranked by verification level then recency; plan tier is never a ranking input.

10 verified providers headquartered in United Kingdom carry a cross-referenced (L2) or higher Application security delivery record. Order is earned: highest verification level first, ties broken by most-recent verification. A free-plan provider always outranks a paid-plan provider with weaker evidence.

Most recent verification in this market: 2026-07-05. Every listing below carries its own last-verified date — the signal that cannot be gamed.

Verified providers

RiverSafe

London, United Kingdom

Developer-friendly AppSec, DevSecOps and cyber consulting for UK enterprise

Application secu…Vulnerability ma…SOC & MDR monito…
records
1
team
50-200
founded
2010

Verified at L2 · unclaimed. Claim it free to respond to buyers and climb to a client-verified rating. Claim it free →

Pentest People

Leeds, United Kingdom

Yorkshire-based CREST/CHECK pentest specialists delivering consultant-led PTaaS via SecurePortal

Penetration test…Vulnerability ma…Application secu…+1 more
records
1
team
50-200
founded
2018

Verified at L2 · unclaimed. Claim it free to respond to buyers and climb to a client-verified rating. Claim it free →

Pen Test Partners

Buckingham, United Kingdom

CREST-approved CSIRT and DFIR from the UK's largest independent security consultancy

Incident responsePenetration test…Red teaming+1 more
records
1
team
100-250
founded
2010

Verified at L2 · unclaimed. Claim it free to respond to buyers and climb to a client-verified rating. Claim it free →

Pentest Limited

Manchester, United Kingdom

Human-led penetration testing and adversary simulation

Red teamingPenetration test…Application secu…+1 more
records
1
team
50-100
founded
2001

Verified at L2 · unclaimed. Claim it free to respond to buyers and climb to a client-verified rating. Claim it free →

OnSecurity

Bristol, United Kingdom

Productised, CREST-accredited pentest-as-a-service for the UK mid-market

Penetration test…Vulnerability ma…Red teaming+1 more
records
1
team
50-200
founded
2018

Verified at L2 · unclaimed. Claim it free to respond to buyers and climb to a client-verified rating. Claim it free →

MDSec

Macclesfield, United Kingdom

Adversary-simulation specialists behind the Web Application Hacker's Handbook

Penetration test…Red teamingApplication secu…+1 more
records
1
team
50-200
founded
2011

Verified at L2 · unclaimed. Claim it free to respond to buyers and climb to a client-verified rating. Claim it free →

Cyphere

Altrincham, United Kingdom

CREST-accredited cyber security services for the whole attack surface

Threat huntingPenetration test…Red teaming+2 more
records
1
team
2-10
founded
2020

Verified at L2 · unclaimed. Claim it free to respond to buyers and climb to a client-verified rating. Claim it free →

Looking wider? See all Application security providers across every market, or every verified AI builder in United Kingdom.

Common questions

How many verified Application security providers are there in United Kingdom?
Trustgent lists 10 verified Application security providers headquartered in United Kingdom. Every listing carries a cross-referenced (L2) verification level or higher, meaning independent third-party signals corroborate the capability claim. Ranking is plan-blind: verification level, contributing record count, and recency are the only signals used.
What does “L2 verified” mean at Trustgent?
L2 (cross-referenced) means Trustgent has independently corroborated the provider’s Application security capability claim via at least three independent public sources — company registry, leadership team on LinkedIn or Crunchbase, and one or more capability attestations (case studies, published talks, open-source contributions, partner-program certifications). L3, L4, and L5 add client-authorized evidence and structured interviews on top.
How is a provider’s rank determined on this page?
Trustgent’s ranking function uses three signals only: verification level (L2 through L5), contributing record count, and most-recent verification date. Plan tier is never an input. A free-plan provider always outranks a paid-plan provider with weaker evidence. The rule is enforced by a hardcoded allowlist in the ranking code; see the Trustgent Attestation Protocol for the formal specification.
How often is verification refreshed?
Every verified record on Trustgent expires after 90 days unless re-attested. L5 (continuously monitored) providers agree to rolling audit and a live freshness gate. A provider’s tier drops automatically if the cadence lapses. The last-verified date appears on every listing so buyers can see exactly how fresh a claim is.
How do I evaluate an AI implementation partner beyond the demo?
Trustgent’s methodology at /how-we-verify sets out a six-level scale (L0 through L5) buyers can use directly. Ask for evidence at the level you need: for L3+ ask for client-authorized case-study documentation; for L4+ ask for structured client-reference interview notes.
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