VoIP Security Checklist 2026: How to Protect Your Calls, Data & Phone System Quick Answer
VoIP security means protecting your internet-based phone system from call interception, account takeover, toll fraud, spoofing, data breaches, downtime, weak passwords, insecure remote access and poor call recording practices.
The safest business VoIP setups use encrypted signalling and media, strong passwords, multi-factor authentication, secure admin portals, patched devices, firewall rules, fraud alerts, call spend controls, secure call recording storage and clear GDPR processes.
For UK businesses, VoIP security is especially important in 2026 because traditional landlines and PSTN-reliant devices need to be upgraded to digital technology by January 2027. Moving calls online can improve flexibility, but it also means your phone system must be protected like any other cloud service.
Before choosing a VoIP provider, ask whether they support:
TLS and SRTP encryption
multi-factor authentication
secure admin access
fraud monitoring
outbound call limits
DDoS protection
secure call recording
UK or GDPR-compliant data storage
remote worker controls
business continuity and failover
clear support response times
Compare secure VoIP providers before switching, especially if your business records calls, handles customer data, takes payments, runs sales or support teams, or depends on phone calls for revenue.
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Authored by: Ally Cox (Business Technology & B2B Services Specialist 10+ Years’ Experience)
Reviewed by: James Ward (Telecoms Specialist, 12+ Years Experience)
Last Updated: July 2026
Contents:
What Is VoIP Security?
Why Does VoIP Security Matter in 2026?
Top VoIP Threats UK Businesses Face
VoIP Security Checklist: The Essentials
How Much Does Secure VoIP Cost?
Is Secure VoIP Worth It?
Key Takeaways
VoIP is secure when it is configured properly, but weak passwords, exposed admin portals and poor network setup can create risk.
Business VoIP should use encryption such as TLS for signalling and SRTP for voice media where available.
MFA should be used for admin portals and user accounts wherever possible.
Call recordings can contain personal data, so access, retention and storage need to be controlled.
Businesses should restrict international, premium-rate and high-risk outbound calling where it is not needed.
Remote workers need secure apps, strong authentication and clear device rules.
DDoS protection matters if your business depends heavily on inbound calls.
Desk phones, softphone apps, routers and PBX software should be patched regularly.
The UK PSTN switch-off means businesses moving from landlines to VoIP should assess security before migration.
Secure VoIP is not just a technical issue. It affects customer trust, GDPR, uptime and fraud prevention.
The cheapest VoIP provider may not be the best option if it lacks encryption, support, monitoring or fraud controls.
Compare VoIP providers based on security, support and reliability, not just monthly price.
VoIP Security at a glance
Security area What to check Why it matters
Encryption
TLS for signalling and SRTP for voice media
Helps protect calls from interception
Passwords
Strong unique passwords for users and admin accounts
Reduces account takeover risk
MFA
Multi-factor authentication for portals and users
Adds protection if passwords are stolen
Admin access
Restricted admin logins and role-based permissions
Prevents unnecessary access
Call fraud controls
Spend caps, premium-rate blocking and geo-blocking
Firewall rules
Secure SIP, RTP and admin access rules
Device patching
Updated desk phones, apps, routers and PBX software
Fixes known vulnerabilities
Remote workers
Secure apps, VPN where needed and managed devices
Protects home and mobile users
Call recording
Encrypted storage, access controls and retention rules
Supports GDPR and data protection
DDoS protection
Provider-level monitoring and mitigation
Backups
Exportable settings and recovery processes
Helps restore service after incidents
Provider security
ISO 27001, SLAs, data centres and incident response
Shows stronger governance
Need a secure business VoIP phone system? This quote service is best for UK businesses that want to compare:
secure hosted VoIP
cloud phone systems
business VoIP providers
VoIP with encryption
VoIP with call recording
VoIP with fraud monitoring
VoIP for remote teams
Microsoft Teams Phone
SIP trunking
Cloud PBX
contact centre VoIP
VoIP for regulated businesses
VoIP migration before the PSTN switch-off
What Is VoIP Security? VoIP security refers to the tools, policies and technologies used to protect internet-based calls from:
Cyberattacks
Eavesdropping
Account takeover
Data theft
Fraudulent call routing
Downtime and DDoS attacks
Because VoIP runs on IP networks rather than copper lines, it must be protected just like any cloud-based system our business uses.
Why Does VoIP Security Matter in 2026? 1. Businesses are moving away from landlines
Traditional PSTN-reliant devices, including UK landlines, need to move to digital technology by January 2027, which means more businesses are moving voice calls onto broadband, cloud phone systems, SIP trunks and hosted VoIP.
This can improve flexibility, but it also means the phone system needs proper cyber security controls.
2. VoIP runs over internet-connected systems
VoIP can involve:
cloud platforms
user accounts
admin portals
desk phones
softphone apps
mobile apps
routers
firewalls
SIP trunks
call recordings
CRM integrations
Any weak point can create a risk.
3. Call data can be sensitive
Business calls may include:
names
phone numbers
addresses
payment discussions
account details
health information
employee information
complaints
sales notes
customer service records
call recordings
voicemail messages
If your business stores or uses personal information, data protection rules apply.
4. Phone downtime can stop sales and support
If your phone system is unavailable, customers may not be able to reach you.
This matters for:
sales teams
support teams
booking teams
clinics
tradespeople
emergency contacts
care providers
hotels
schools
call centres
appointment-based businesses
5. VoIP fraud can become expensive quickly
If attackers compromise your phone system, they may make high-cost calls, redirect calls, access voicemail or use your system for fraud, so outbound call controls and fraud alerts are essential.
Main VoIP security risks for UK businesses
Risk What it means How to reduce it
Call interception
Attackers try to listen to calls or capture voice traffic
Use TLS/SRTP and secure networks
Account takeover
A user or admin account is compromised
Use MFA, strong passwords and access reviews
Toll fraud
Attackers make expensive calls through your system
Set spend caps, call barring and alerts
SIP spoofing
Attackers impersonate calls or abuse SIP traffic
Use secure SIP settings and provider controls
Vishing
Fraudsters use calls for social engineering
Train staff and verify caller identity
DDoS attacks
Attackers overwhelm services and cause downtime
Choose providers with monitoring and mitigation
Insecure call recordings
Recordings are accessed, shared or stored incorrectly
Use encryption, permissions and retention rules
Poor remote access
Staff use insecure Wi-Fi or unmanaged devices
Use secure apps, MFA and device policies
Unpatched devices
Old firmware or apps expose vulnerabilities
Patch phones, apps, routers and PBX software
Weak admin controls
Too many people have high-level access
Use role-based access and audit logs
Poor number porting controls
Numbers are moved or redirected without proper checks
Use provider controls and documented processes
No incident plan
Staff do not know what to do when calls fail
Create a response and recovery plan
VoIP Security Checklist: The Essentials 1. Use encrypted VoIP where available
Your provider should support secure protocols such as:
TLS for signalling
SRTP for voice media
HTTPS for admin portals
secure APIs for integrations
Ask your provider:
Is TLS enabled by default?
Is SRTP available?
Are calls encrypted between endpoints and provider infrastructure?
Are admin portals protected with HTTPS?
Are call recordings encrypted at rest?
Are backups encrypted?
Avoid assuming all VoIP is encrypted automatically. Ask for the details.
2. Enforce strong passwords and MFA
Weak passwords are one of the easiest ways for attackers to compromise VoIP systems, so use:
strong unique passwords
no shared admin logins
multi-factor authentication
password managers
separate admin accounts
login alerts
regular access reviews
Apply MFA to:
admin portals
user portals
softphone accounts
Microsoft 365 accounts
CRM integrations
support portals
billing portals
If your provider does not support MFA, compare alternatives.
3. Lock down admin access
Your VoIP admin portal controls users, numbers, call routing, voicemail, call recordings and sometimes billing, so you should restrict admin access by:
giving admin rights only to people who need them
using role-based permissions
removing old users
reviewing access quarterly
enabling login alerts
restricting access by IP address where possible
keeping a record of who can change call routing and billing settings
A compromised admin account can be much more damaging than a normal user account.
4. Protect against toll fraud
Toll fraud happens when attackers use your phone system to make expensive calls – reduce risk by using:
international call blocking
premium-rate number blocking
spend limits
user-level call permissions
geo-blocking
unusual call alerts
out-of-hours call restrictions
call forwarding controls
daily spend alerts
provider fraud monitoring
Ask your provider:
Do you monitor unusual call patterns?
Can I block international calls?
Can I restrict calls by user?
Can I set monthly spend alerts?
What happens if fraud is detected overnight?
5. Segment VoIP traffic on your network
Where possible, separate VoIP traffic from other business traffic.. This can mean:
using a dedicated VLAN for VoIP
separating guest Wi-Fi from business devices
keeping IoT devices away from VoIP phones
applying firewall rules
restricting unnecessary ports
using secure Wi-Fi for softphones
avoiding open public Wi-Fi for business calls
6. Keep devices, apps and firmware updated
VoIP security depends on keeping all connected components updated.
Patch and review:
desk phones
softphone apps
mobile apps
routers
firewalls
switches
PBX software
operating systems
Microsoft Teams
CRM integrations
call recording platforms
Create a simple patching routine:
Item
Softphone apps
Monthly
Desk phone firmware
Quarterly
Router/firewall firmware
Quarterly
PBX software
Monthly or vendor-recommended
User access
Quarterly
Call routing
Quarterly
Call recording access
Quarterly
Provider security settings
At renewal and after major changes
7. Choose a provider with DDoS protection
A denial-of-service attack can make a system unavailable by overwhelming it with traffic – for VoIP, this can mean:
missed inbound calls
failed outbound calls
poor call quality
delayed support
lost sales
business disruption
Ask your provider:
Do you monitor for denial-of-service attacks?
Do you offer DDoS mitigation?
How do you protect hosted VoIP infrastructure?
What is your incident response process?
What uptime SLA do you offer?
What happens if your service is unavailable?
If phones are business-critical, provider resilience matters.
8. Secure remote and hybrid workers
Remote VoIP users create extra risk because they may use home broadband, public Wi-Fi, personal devices or unmanaged laptops, so for remote teams:
use MFA
use approved apps
avoid public Wi-Fi for calls
use VPN or secure tunnels where required
use company-managed devices where possible
enable device locks
keep apps updated
remove access when staff leave
use mobile device management for larger teams
restrict voicemail and recording access
train staff on phishing and vishing
Remote VoIP security should be part of your wider remote working policy.
9. Secure call recordings and voicemail
Call recordings and voicemails can contain personal or sensitive information, so your business should control:
who can access recordings
how long recordings are kept
where recordings are stored
whether recordings are encrypted
whether recordings can be downloaded
whether recordings can be emailed
whether recordings are logged
how data subject access requests are handled
how recordings are deleted
whether customers are told calls are recorded
Do not record calls simply because the feature is available. Have a clear reason and retention policy.
10. Review GDPR and data protection requirements
VoIP data can often include personal information which can include:
caller numbers
names
call logs
voicemail
call recordings
CRM notes
call transcripts
billing data
support tickets
employee call records
UK businesses should consider:
lawful basis for processing
call recording notices
retention periods
access controls
subject access requests
data processor agreements
data storage location
international transfers
breach reporting processes
staff monitoring rules
employee privacy notices
If you record calls for training, monitoring, compliance or dispute resolution, make sure your data protection processes match the way you actually use recordings.
11. Protect voicemail and call forwarding
Voicemail and call forwarding are often overlooked, so secure them by:
setting strong voicemail PINs
disabling default PINs
blocking remote voicemail access if not needed
monitoring call forwarding changes
restricting forwarding to international numbers
reviewing out-of-hours routing
removing old voicemail boxes
deleting unnecessary voicemail recordings
checking shared mailbox access
12. Train staff on vishing and call fraud
VoIP systems can be used in social engineering attacks so train your staff to be suspicious of callers who:
ask for passwords
request payment changes
create urgency
impersonate suppliers
impersonate banks
request remote access
ask to bypass procedures
claim to be from IT support
pressure staff to share customer data
13. Create a VoIP incident response plan
Create a simple plan for what happens if:
phones go down
calls are being redirected
call quality collapses
fraud is suspected
a user account is compromised
recordings are exposed
the provider has an outage
a remote worker loses a device
numbers are ported incorrectly
customers cannot reach you
Your plan should include:
provider support contacts
internal decision owners
backup numbers
call forwarding options
incident logging
customer communication templates
password reset process
fraud response steps
reporting requirements
post-incident review
VoIP Security by business type
Business type Main security concern
Sole trader
Personal/business number separation
App security, MFA and voicemail PINs
Small office
User access and call routing
MFA, admin controls and provider support
Sales team
CRM data and call recording
Recording controls, CRM permissions and fraud alerts
Support team
Customer data and call queues
Access control, recording retention and uptime
Remote team
Devices and home networks
MFA, secure apps and device policies
Healthcare or clinic
Sensitive call content
Call recording rules, access control and secure storage
Legal or finance firm
Confidential calls
Encryption, call logs, recording access and audit trails
Retail or hospitality
Availability and missed calls
Failover, call forwarding and provider support
Multi-site business
Network consistency
Centralised admin, permissions and resilience
School or public sector
Safeguarding and continuity
Compliance, access control and incident response
How Much Does Secure VoIP Cost? Secure VoIP does not always cost more than standard VoIP, but some security and compliance features may sit on higher plans.
Business size Typical monthly cost
Security features to check
1-5 users
£8-£20 per user
MFA, encryption, secure apps, voicemail PINs
6-20 users
£10-£25 per user
Admin controls, call routing, fraud alerts
20-50 users
£15-£30+ per user
Call recording, reporting, permissions, support
Sales/support team
£30-£100+ per user/agent
Recording, analytics, CRM integration, queues
Multi-site business
Custom pricing
Failover, resilience, SLAs and centralised admin
Is Secure VoIP Worth It? Yes, a single VoIP breach can cost UK SMEs thousands in fraud, downtime or GDPR penalties. We think that investing in secure VoIP protects your calls, data and brand reputation.
If you do any of the following, we recomend it:
record calls
handle customer data
take sales calls
run support teams
take bookings
discuss payments
use remote workers
use Microsoft Teams Phone
connect VoIP to a CRM
have multiple users
need reliable inbound calls
are replacing landlines before the PSTN switch-off
VoIP security and GDPR VoIP can create and store personal data, and your business may process personal data through:
call logs
phone numbers
caller names
account information
voicemail
call recordings
transcripts
CRM integrations
call notes
employee monitoring reports
To reduce GDPR risk, ask:
What call data is collected?
Why do we collect it?
How long do we keep it?
Who can access it?
Where is it stored?
Is it encrypted?
Can users download recordings?
Are callers told if calls are recorded?
Is call monitoring explained to staff?
Do we have a data processing agreement with the provider?
Can we respond to data subject access requests?
What happens if there is a breach?
Secure call recording checklist If your business records calls, use this checklist.
Check Why it matters
Clear reason for recording
Avoids recording calls unnecessarily
Caller notice
Helps meet transparency expectations
Staff notice
Supports employee privacy and monitoring compliance
Access permissions
Prevents unnecessary access to recordings
Encryption
Protects recordings if systems are compromised
Retention period
Stops recordings being kept forever
Download controls
Reduces risk of recordings being shared
Audit logs
Shows who accessed recordings
Deletion process
Helps remove data when no longer needed
DSAR process
Helps respond to personal data requests
Secure storage location
Supports GDPR and data governance
Provider contract
Clarifies processor responsibilities
What to ask your VoIP provider before signing Ask these questions before choosing a VoIP provider:
Is TLS/SRTP supported?
Is MFA available?
Are admin permissions role-based?
Can we block international and premium-rate calls?
Do you monitor for toll fraud?
Do you offer DDoS protection?
Are call recordings encrypted?
Where is call data stored?
Can we set recording retention periods?
What support is available during an outage?
What happens if a user account is compromised?
Can we remove users immediately?
Is number porting secure and documented?
Do you provide a data processing agreement?
Can we get audit logs?
Do you support remote workers securely?
What is included in setup and onboarding?
What are the cancellation terms?
If a provider cannot answer basic security questions clearly, compare alternatives.
FAQs About VoIP Security Is VoIP secure in the UK in 2026?
Yes, VoIP can be secure when it is configured properly. Businesses should use encryption, strong passwords, MFA, secure admin access, patched devices and a provider with fraud monitoring and resilience.
Can VoIP be hacked?
Yes. VoIP can be hacked if accounts, admin portals, SIP credentials, devices or networks are poorly secured. Common risks include toll fraud, call interception, spoofing and account takeover.
What is the biggest VoIP security risk?
For many small businesses, the biggest risks are weak passwords, no MFA, poor admin controls, insecure remote access and lack of fraud monitoring.
What is VoIP toll fraud?
Toll fraud happens when attackers use your phone system to make unauthorised calls, often to expensive international or premium-rate numbers.
How do I stop VoIP toll fraud?
Use strong passwords, MFA, call barring, international call blocking, premium-rate blocking, spend limits, fraud alerts and provider monitoring.
What is TLS in VoIP?
TLS is Transport Layer Security. In VoIP, it helps protect signalling information used to set up and manage calls.
What is SRTP in VoIP?
SRTP is Secure Real-Time Transport Protocol. It helps protect the voice media part of a VoIP call.
Do I need end-to-end encryption for VoIP?
Not every business VoIP system uses true end-to-end encryption. Many secure business systems use TLS and SRTP. Ask your provider what is encrypted and where encryption starts and ends.
Does VoIP need a VPN?
Not always. A VPN may be useful for some remote workers or admin access, but many cloud VoIP apps can be secure without a VPN if they use strong authentication, encryption and managed access.
Is call recording allowed under GDPR?
Call recording can be allowed, but businesses need a valid reason, transparency, secure storage, access controls and retention rules. If recordings contain personal data, UK data protection rules apply.
Are voicemail messages personal data?
They can be if they identify a person or contain information about them. Businesses should protect voicemail access and delete messages when no longer needed.
How long should VoIP call recordings be kept?
There is no single answer for every business. You should set a retention period based on why recordings are needed, then delete recordings when they are no longer required.
Should small businesses use MFA for VoIP?
Yes. MFA is strongly recommended for admin portals, user accounts, Microsoft 365, softphones and any system connected to business calls.
How can remote workers use VoIP securely?
Remote workers should use approved apps, strong passwords, MFA, secure devices, updated software and trusted networks. Businesses should remove access quickly when staff leave.
Can DDoS attacks affect VoIP?
Yes. A denial-of-service attack can make services unavailable or degrade call quality. NCSC guidance says organisations should understand and manage denial-of-service risk.
What should I look for in a secure VoIP provider?
Look for encryption, MFA, fraud monitoring, call barring, DDoS protection, secure call recording, UK or GDPR-compliant data storage, strong support, SLAs and clear incident response processes.
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Hi, I’m Ally Cox , a senior copywriter and blogger at CompareYourBusinessCosts.co.uk, the UK’s trusted platform for comparing business services.over a decade of experience in the B2B sector, I specialise in simplifying complex topics like leased lines, VoIP, business energy, HR and payroll solutions, accounting software, and EPOS systems .HR, copywriting, and business operations- from clocking-in systems to card machines and office technology .informed, confident decisions when choosing products and services that improve efficiency and save money.
