What Is Endpoint Security? A Guide for UK SMEs

What counts as an endpoint?

An endpoint is any device that connects to a business network or cloud service. For UK SMEs the highest-risk endpoints are the everyday machines staff use to open email and access company data — and since 2020, most of them now operate outside the office network entirely.

• Laptops and desktops (Windows, macOS) — the primary devices for office-based and remote staff
• Mobile phones and tablets (iOS, Android) — including personal devices under bring-your-own-device (BYOD) policies
• Servers — on-premises physical servers and cloud virtual machines in Azure, AWS, or similar
• Network-attached storage (NAS) devices holding shared files and backups
• Point-of-sale terminals, specialist equipment, and industrial control systems in certain sectors

The threat is concrete. According to the DSIT Cyber Security Breaches Survey 2025, 43% of UK businesses experienced a cybersecurity breach or attack in the past 12 months, equating to approximately 612,000 businesses, with 67% of medium businesses and 74% of large businesses reporting breaches in 2025. Many of those breaches begin at the endpoint — a phishing email opened on a laptop, malware on a workstation, or a compromised phone.

Traditional antivirus vs modern EDR — what's the difference?

The difference is detection method. Traditional antivirus matches files against a database of known malware signatures and blocks what it recognises. Modern endpoint detection and response (EDR) watches device behaviour in real time and catches threats it has never seen before — then acts to contain them.

Traditional antivirus is passive and reactive: it waits for a known threat to appear, then quarantines it. It cannot stop fileless attacks, living-off-the-land techniques that misuse legitimate tools like PowerShell, or sophisticated multi-stage intrusions. EDR continuously monitors process activity, network connections, file modifications, and registry changes, using behavioural analytics to flag malicious patterns regardless of whether the specific malware has been catalogued. When it detects a threat, it can isolate the device, terminate processes, roll back changes, and alert analysts.

This is why EDR has replaced antivirus as the standard for business endpoint protection. Antivirus is a single layer of passive defence; EDR is active, intelligent, and responsive.

How does AI-based detection work?

AI-based detection establishes a baseline of normal behaviour for each device and user, then flags deviations that match attack patterns or anomalous activity. Modern EDR platforms — including Microsoft Defender for Business — train machine-learning models on billions of endpoint events to recognise malicious behaviour, not just known files.

That behavioural approach is what catches never-before-seen malware: software attempting to disable security tools, encrypting files in rapid succession, or opening covert network connections gives itself away by what it does. AI detection also identifies fileless attacks running entirely in memory. This matters because the DSIT Cyber Security Breaches Survey 2025 found that 85% of breaches involved phishing, and phishing payloads are routinely engineered to slip past signature-based antivirus.

What does managed endpoint security include?

Managed endpoint security goes beyond installing EDR agents. It pairs the detection technology with people who investigate and act on what it finds — the gap most SMEs cannot fill in-house. A complete service covers deployment, monitoring, investigation, containment, and reporting.

• Deployment and configuration of EDR agents on every endpoint, with policies tuned to your risk profile
• Continuous monitoring of alerts by qualified analysts, separating genuine threats from false positives
• Active investigation — examining the full context of an alert to gauge scope and severity
• Incident containment — isolating compromised devices, terminating processes, revoking credentials
• Remediation guidance — clear steps for recovery, re-imaging, and restoring data
• Patch management support — keeping operating systems and applications current
• Monthly reporting on endpoint status, threat volumes, and actions taken

The DSIT Cyber Security Breaches Survey 2025 found that only 14% of UK businesses have a formal incident response plan. A managed detection and response service fills that gap by providing expert response capability whenever an endpoint threat appears, day or night.

Microsoft Defender for Business and the managed layer

For UK SMEs on Microsoft 365, Microsoft Defender for Business is the primary endpoint protection solution. It provides EDR, automated investigation and response, attack surface reduction rules, and network protection, managed through the Microsoft 365 Defender portal. It is included in Microsoft 365 Business Premium (£16.90 per user per month, ex VAT, annual — see Microsoft 365 pricing), making it cost-effective for businesses already on the platform.

Detection technology alone is not enough — someone must investigate and act on the alerts it produces. AMVIA's in-house 24/7 SOC adds a human-led layer on top of Microsoft Defender, providing around-the-clock threat hunting and incident response by dedicated analysts. Microsoft Defender provides the detection; our analysts provide the expertise to investigate alerts, eliminate false positives, and respond to confirmed threats. One provider, security-first, Microsoft-certified.

Why does endpoint security need 24/7 SOC monitoring?

Because EDR detects threats, but a human has to investigate and respond. A 24/7 Security Operations Centre provides continuous monitoring of endpoint alerts — triaging events, investigating genuine threats, and containing incidents before they escalate. For SMEs without in-house security staff, round-the-clock coverage means threats are handled at any hour, not whenever someone next checks a dashboard.

The case for speed is blunt. Ransomware can encrypt an entire network in under an hour. Stolen credentials can give an attacker persistent access they exploit days later. Without continuous monitoring, these threats persist undetected and do far more damage than if caught immediately. An alert generated at midnight that sits until morning is an open door — and 19,000 UK businesses were hit by ransomware in 2025 (Sophos).

What does managed EDR cost for UK SMEs?

Managed endpoint detection and response for UK SMEs typically costs between £5 and £15 per device per month, depending on provider, scope, and whether 24/7 SOC monitoring is included. For a 50-person business with 60 endpoints, that is roughly £3,600 to £10,800 per year.

Set that against the alternatives. A single in-house security analyst costs £40,000 to £60,000 per year (typical UK 2026 range). The average cost of the single most disruptive breach was approximately £1,205 for micro and small businesses (DSIT Cyber Security Breaches Survey 2025) — and the operational disruption, data loss, and reputational damage from a serious endpoint compromise can run far higher.

How AMVIA secures endpoints for UK SMEs

AMVIA deploys and manages Microsoft Defender for Business across all client endpoints, monitored by our in-house managed SOC for 24-hour threat hunting and human-led response. We manage patching, monitor alerts, investigate incidents, and report monthly on endpoint status. Our Sheffield-based team is available around the clock to respond to genuine threats — enterprise-grade protection at a predictable monthly cost. We hold Cyber Essentials Plus and work as a Microsoft Solutions Partner, so the people configuring your defences are certified on the platform they run.

For practical hardening guidance, the NCSC's device security guidance is a sound reference for any UK business setting its baseline.