What Are the Security Risks of VoIP for Businesses?
Because VoIP runs over the internet, it shares the same attack surface as any networked system, plus some risks unique to voice. For UK businesses, this matters: Ofcom, GDPR and PCI DSS all have direct implications for how you secure your phone system. Here's what the real threats look like, and what good protection addresses.
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What Are the Main VoIP Security Threats and How Are They Mitigated?
| VoIP security threat | What can happen | How it is mitigated |
|---|---|---|
| Toll fraud | Criminals gain access and make expensive unauthorised calls | Restrict premium/international calls, monitor unusual call activity, and use strong SIP credentials |
| Eavesdropping | Calls may be intercepted on insecure networks | Use SRTP for voice, TLS for signalling, and secure network infrastructure |
| SIP scanning & brute-force attacks | Attackers try to access SIP accounts and register rogue extensions | Use IP allowlisting, an SBC, rate limiting, and strong authentication |
| Denial of service attacks | Flooding can disrupt phone services and take lines offline | Use redundant infrastructure and multiple data centres |
| Vishing / voice phishing | Attackers impersonate trusted organisations to obtain information or authorise payments | Train staff to verify callers through a separate communication channel |
| GDPR & PCI DSS risks | Insecure recordings or data handling can create compliance problems | Use secure storage, encryption, and a provider that meets relevant compliance requirements |
How Does VoIP Stay Compliant With GDPR and PCI DSS?
If your business handles personal data or card payments over the phone, your VoIP system must meet the relevant regulatory standards. Non-compliant call recording, insecure data storage and unencrypted transmission can all result in significant fines. Look for a provider that is UK GDPR compliant, PCI DSS certified and ICO registered, and can evidence it.
Should Security Be a Premium Add-On?
No, it should be built into the platform. At The VoIP Shop, that's how we run it: we are Cyber Essentials Certified, UK GDPR compliant (via Naq), PCI DSS certified, NHS DSP Toolkit approved, and ICO registered (reference ZA476885). Our infrastructure runs on Telehouse London Tier 1 data centres, the same standard used by major UK financial institutions.
If poor call quality is affecting you alongside security concerns, our call quality fix guide covers the network-level checks that often resolve both at once.
How Do I Know If My Current Phone System Meets These Standards?
If you're unsure, we offer a free security-focused VoIP consultation. Our UK-based team can review your current setup against Ofcom, GDPR and PCI DSS requirements and flag any gaps.
Speak to a specialist on 0116 402 2222 or get in touch via our website to book a consultation.
Written By | About the Author
Kully has over 15 years of experience in the VoIP and telecoms industry. Drawing on a background in telecoms sales and leadership, he provides expert, impartial advice on VoIP and cloud telephony solutions. As a lead author for The VoIP Shop, Kully helps businesses understand and adopt modern communication technologies