Resources
Practical, defensive telephony security
Clear guidance for IT and security teams on securing phone systems and reducing fraud risk. Educational and defensive, with no operational attack detail.
Guides
Security guides
- 8 min read
How to secure a business PBX: a practical review
A defensive, step-by-step way to review a business phone system (exposure, accounts, dialling, patching and monitoring), written for IT teams.
Read the guide → - 7 min read
SIP security fundamentals: why telephony fraud starts here
What SIP exposure is, why attackers target it, and the controls that reduce the risk: a clear, defensive primer for IT and security teams.
Read the guide → - 6 min read
Toll fraud explained: how phone systems become a bill
How toll fraud works at a high level, who pays for it, why provider caps are not enough, and how to reduce the exposure: a defensive overview.
Read the guide → - 9 min read
Caller-ID spoofing and vishing: a defensive guide
How caller-ID spoofing and voice phishing work, why they matter for organisations with phone systems, and the defensive controls that reduce the risk.
Read the guide → - 10 min read
SIP registration security: preventing rogue endpoints
How SIP registration works, why weak registration authentication lets attackers register rogue endpoints and drive toll fraud, and the controls that stop it.
Read the guide → - 9 min read
SRTP and media encryption for VoIP, explained
What SRTP is, why plain RTP media can be intercepted, how media encryption is keyed, and how to verify your VoIP calls are actually protected end to end.
Read the guide → - 13 min read
The complete guide to VoIP security
A defensive, UK-focused guide to securing business VoIP end to end: the attack surface, transport and signalling encryption, media protection with SRTP, endpoints and softphones, hosted versus on-premises responsibilities, fraud, and independent assessment.
Read the guide → - 12 min read
The complete guide to PBX security
A defensive, UK-focused guide to securing a modern PBX: external exposure, authentication, management interfaces, dial-plan design, patching, encryption, logging and independent assessment against NCSC guidance.
Read the guide → - 10 min read
The complete guide to SIP security
A defensive guide to SIP security for UK organisations: how the protocol works, why fraud so often starts here, trunk and registration exposure, authentication, transport security, routing and how an authorised SIP audit works.
Read the guide → - 9 min read
Preventing PBX toll fraud: a defensive guide
A defensive guide to PBX toll fraud for UK organisations: how it happens at a high level, who bears the cost, the controls that stop it, the scale of the problem and why an authorised assessment closes the paths.
Read the guide → - 9 min read
Cloud PBX vs on-premises PBX: the security differences
A practical UK comparison of cloud and on-premises PBX security as the PSTN switch-off drives businesses onto IP telephony, covering exposure, patching, the shared-responsibility model, authentication, and what an authorised assessment covers for each.
Read the guide → - 11 min read
How a PBX security assessment works, step by step
A defensible, standards-aligned methodology for an authorised PBX security assessment, from authorisation and discovery through fingerprinting, validation, prioritisation, reporting, remediation and ongoing assurance.
Read the guide → - 13 min read
The 2026 buyer's guide to PBX and VoIP security testing
A comprehensive buyer's guide to commissioning PBX and VoIP security testing in 2026: what a good assessment includes, scoping and authorisation, technical coverage, reporting standards, retesting, cost drivers, and how to compare suppliers.
Read the guide → - 8 min read
Automated PBX assessment vs traditional penetration testing
A fair comparison of automated PBX assessment and traditional penetration testing across repeatability, telephony focus, cost, human validation and evidence, and where each fits.
Read the guide → - 7 min read
Continuous PBX assurance vs an annual assessment
Why a point-in-time PBX assessment decays as estates change, and the honest case for scheduled automated reassessment, human-validated, rather than always-on real-time monitoring.
Read the guide → - 7 min read
PBX security assessment vs vulnerability scanning
How a telephony-focused PBX security assessment differs from generic vulnerability scanning on context, validation, toll-fraud demonstration and dial-plan review.
Read the guide → - 7 min read
NCSC PBX security guidance: a practical checklist
A practical checklist drawn from the NCSC's PBX best-practice guidance, with the official source linked and notes on where an authorised assessment helps you evaluate the controls.
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Tools
Put it into practice
Checklist
The Business PBX Security Checklist
A working checklist your IT team can use to review external exposure, accounts, dialling, patching and monitoring.
Read moreInteractive
PBX Security Self-Assessment
Answer twelve questions and get an indicative posture band and a recommended next step. It is not a penetration test.
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Find out exactly how exposed your phone system is
Request an authorised PBX, VoIP or SIP security assessment. We confirm scope and authorisation first, then show you what is exposed and what to fix.
Testing is only performed against systems you own or are explicitly authorised to test.