Microsoft Solutions
Business Solutions
Microsoft for Business
Join us at our next event
By Industry
How we help
BlogSecurity

Zero Trust: What SMEs Need to Know (and How to Get Started)

10 Dec, 2025
Cyber-secured doors with one unlocked in the middle

For years, cybersecurity was simple: build a strong perimeter and trust everything inside. Think of it as the old castle-and-moat approach, once you crossed the drawbridge, you were in.

But in 2025, that approach doesn’t cut it anymore. Remote work, cloud apps, mobile devices, and insider threats mean the walls are down. Attackers know it, and they’re exploiting it.

In fact, 80% of breaches involve compromised credentials or stolen passwords (Verizon DBIR, 2025).

That’s where Zero Trust comes in.

The principle is simple: Never trust. Always verify.

What Is Zero Trust?

Think of Zero Trust as a new way of thinking – not a product you buy, but a mindset you adopt. It starts with one assumption: don’t automatically trust anyone, inside or outside your network.

Instead, every user, device, and application must prove its legitimacy every time. Access is limited to what’s necessary, and activity is continuously monitored.

Think of it like this: You’ve finished work for the day and locked your front door, would you leave your windows wide open and trust that nobody would enter? Of course not!

Because in today’s world, leaving those “windows” open is exactly what happens when you assume trust. Zero Trust closes those gaps by making verification the rule, not the exception – so only the right people, on the right devices, get access when they truly need it.

Why SMEs Should Care

Imagine running a growing business. You’re focused on customers, cash flow, and keeping the lights on. Meanwhile, cybercriminals are watching – because they know smaller firms often have weaker defences. To them, SMEs aren’t just targets; they’re easy wins.

Here’s why:

  • SMEs are prime targets. Criminals often assume smaller firms have weaker defences.
  • Remote work = more risk. Data lives everywhere now: laptops, mobiles, cloud apps.
  • Financial impact hits harder. The average SME spends nearly £8,000 recovering from a serious breach – not including reputational harm or downtime (ByteStart, 2025).
  • Regulatory pressure. A breach caused by weak controls can trigger ICO investigations and fines.

 

For SMEs, Zero Trust isn’t about luxury. It’s about survival.

5 Steps SME's can take to protect themselves

How SMEs Can Start the Journey

01

Turn on MFA everywhere (Microsoft 365, email, banking, apps).

Multi-Factor Authentication adds an extra layer of security beyond passwords.
02

Audit user access - remove old accounts and unnecessary permissions.

Inactive accounts are a hacker’s dream.
03

Use conditional access in Microsoft 365 to restrict risky logins.

This stops attackers exploiting stolen credentials remotely.
04

Encrypt and update devices to block common exploits.

Ensure laptops and mobiles use full-disk encryption.
05

Back up critical data to both the cloud and external storage.

Ransomware thrives on businesses without backups.
06

Train staff to spot phishing, ransomware, and quishing attempts.

Teach employees to verify links, avoid suspicious attachments, and report anything unusual immediately.

Zero Trust Is a Journey, Not a Switch

 

Zero Trust isn’t something you “switch on” overnight. It’s a cultural and technical shift – one that pays dividends in resilience, customer trust, and regulatory compliance.

And it’s not just for enterprises. SMEs have the most to gain by adopting it early, before an attack forces their hand.

At String, we make Zero Trust practical and affordable for growing businesses – helping you put the principles into action with the right mix of Microsoft tools, policies, and ongoing support.

Because in 2025, trust is earned, not given.

Related

How can we help?
Let's Talk