A well-run business VoIP system is secure, but like email it needs sensible settings. The biggest real-world risk is toll fraud: criminals breaking into a phone system to make expensive international calls at your cost.
Common threats
- Toll fraud: unauthorised calls to premium or international numbers.
- Weak passwords: on user accounts, voicemail or desk phones.
- Phishing and social engineering: someone calling your support line pretending to be you.
- Insecure networks: phones on open or unprotected Wi-Fi.
Signs something is wrong
- calls in your logs to countries you do not deal with
- a sudden jump in call charges
- calls happening outside working hours
- voicemail settings changed without anyone asking
Simple steps that prevent most problems
- use strong, unique passwords and change default voicemail PINs
- block international and premium-rate dialling for users who do not need it
- set spending limits and alerts on unusual call activity
- keep desk phone firmware up to date
- remove users as soon as people leave
What to look for in a provider
Ask about fraud monitoring, encrypted calls, two-factor login for the admin portal, and UK-based support you can actually reach. Our guide to choosing a provider has a full checklist.