Business Mobile Security: Protecting Company Data on Phones

A modern company phone holds email, files, cloud logins and often MFA codes — so a lost or unmanaged device hands an attacker a working key to your business. Mobile security closes that gap, and it sits inside our wider business mobile services so the same controls cover every handset you issue. The National Cyber Security Centre recommends device management and a minimum security baseline on every device that touches company data.

What is business mobile security?

Business mobile security is the full set of technical controls, policies and software that protect company data on phones and tablets. It guarantees that every device reaching corporate email, files and apps meets a defined baseline — whether company-owned or personal (BYOD). It treats a phone as an endpoint, not an afterthought.

In practice that baseline covers five things: encryption at rest, strong authentication, mobile device management (MDM) enrolment, controlled app installation, and a tested remote wipe. Miss one and you leave a documented, exploitable gap. AMVIA enforces all five through mobile device management rather than leaving them to each user's good habits.

How does business mobile security work?

Mobile security is enforced through MDM software. Microsoft Intune — included in Microsoft 365 Business Premium at £16.90 per user per month (microsoft.com/en-gb) — is the most widely adopted platform among UK SMEs. Once a device is enrolled, an administrator pushes policy: mandatory PIN or biometric lock, full-disk encryption, an approved app list and VPN configuration.

Conditional Access policies in Microsoft Entra ID work alongside Intune so only compliant, enrolled devices can reach Microsoft 365 email, SharePoint and Teams. A non-enrolled device that tries to pull corporate mail with a correct password is blocked until it meets compliance.

Beyond MDM, a complete strategy adds Mobile Threat Defence (MTD). MTD runs on the device, scanning for malicious apps, phishing links and suspicious networks such as man-in-the-middle attacks on public Wi-Fi. When it finds a threat, it flags the device as non-compliant in Intune, and Conditional Access blocks access until the threat is cleared.

What are the five core mobile security controls?

Every UK business that issues phones or allows personal devices for work should have five controls in place. These are the minimum baseline — each one maps directly to a real attack you are otherwise exposed to.

• Device encryption: all company devices encrypted at rest. iOS encrypts by default once a passcode is set; Android 10+ supports full-disk or file-based encryption. Intune verifies status and blocks unencrypted devices.
• Strong authentication: biometric enable plus a strong alphanumeric passcode as fallback, and MFA for cloud apps. Intune enforces minimum PIN length and complexity across the fleet.
• MDM enrolment: every device enrolled before it is issued, giving the business visibility and control it otherwise has none of.
• Application management: an approved app catalogue, blocked sideloading (critical on Android), and MAM policies that stop data leaking from Outlook into personal apps.
• Remote wipe: a tested process — full wipe for company devices, selective wipe of the work profile for BYOD devices — ready before a device is lost, not after.

Why do UK SMEs need mobile security?

Attackers increasingly target phones because they are often less protected than laptops yet reach the same data. Smishing, malicious apps from unofficial stores and public-Wi-Fi interception are all growing. According to DSIT's Cyber Security Breaches Survey 2025, 43% of UK businesses experienced a cyber breach, with phishing — including attacks delivered via mobile messaging — the most common initial method (gov.uk).

With 28% of UK employees now working in a hybrid pattern (ONS 2025), company smartphones routinely connect to home, hotel and hotspot networks where no corporate perimeter applies. Mobile malware attacks also rose around 50% year-on-year (2024 mobile threat data). Device-level controls are what protect data once the network perimeter is gone.

Under UK GDPR, you are responsible for personal data processed on work phones; a breach from an unmanaged device can trigger an ICO investigation. Cyber Essentials, the UK government-backed scheme AMVIA holds at Plus level, explicitly requires that all devices accessing company data — phones included — meet minimum controls for encryption, access control and patching.

Managed vs unmanaged: what changes

What are the most common mobile security mistakes?

Even businesses that have started on mobile security leave avoidable gaps. The most common is enrolling devices in MDM but never enforcing Conditional Access — so an unenrolled personal device still reaches corporate email with just a username and password.

• Allowing outdated operating systems: old iOS and Android builds carry documented vulnerabilities; Intune can flag and restrict them.
• Untested remote wipe: many have it configured but have never run it, so nobody knows the steps when a device actually goes missing.
• Ignoring Android sideloading: without MDM restrictions, staff install apps from outside the Play Store and import malware.
• Siloing mobile from IT security: phones are endpoints and belong in the same framework as laptops and servers. Linking mobile controls to your wider cybersecurity programme removes the blind spot.

How does AMVIA manage mobile security?

AMVIA configures and runs Microsoft Intune MDM end to end: enrolment, compliance policy, Conditional Access and tested remote wipe. For businesses supplying handsets, we manage the full lifecycle from provisioning to secure disposal, and we integrate every device into the same security framework as the rest of your estate — Microsoft 365 Security included.

Whether you are securing a fleet of company phones or running a controlled BYOD programme, you get one accountable provider, security first, with Microsoft-certified engineers. Call 0333 733 8050 to discuss your mobile security requirements.