Microsoft 365 Security: 7 Settings Every Small Business Should Check

Microsoft 365 is used by many small businesses for email, documents, meetings, file sharing and everyday collaboration. But simply having Microsoft 365 does not mean every security setting has been reviewed. Small businesses should regularly check how accounts, email, devices and company data are protected. Business IT Solutions can help businesses review these settings and identify areas that may need attention. From multi-factor authentication to admin permissions and email protection, a few sensible checks can make a significant difference to your Microsoft 365 security.

Why Microsoft 365 Security Matters for Small Businesses

Microsoft 365 often contains sensitive business information, including emails, customer details, documents, financial information and internal communications. If an account is compromised, an attacker may gain access to much more than an employee’s inbox.

Microsoft provides built-in security features for business subscriptions, including protection against spam, malware and phishing. However, businesses should still review their configuration and make use of the security controls available with their particular Microsoft 365 plan.

Here are seven settings worth checking.

1. Check That Multi-Factor Authentication Is Enabled

A password alone is not always enough to protect a business account. Multi-factor authentication (MFA) adds another verification step when a user signs in.

Microsoft 365 business organisations have security defaults available, and these can require users to register for MFA. Businesses with suitable Microsoft Entra licences can also use Conditional Access for more specific policies.

Check that MFA is active for your users, particularly accounts with access to sensitive information or administration settings.

It is also worth reviewing what happens when an employee loses their phone or changes devices so there is a clear process for account recovery.

2. Review Administrator Accounts

Administrator accounts have access to important Microsoft 365 settings, making them particularly attractive to attackers.

Small businesses should keep the number of administrator accounts limited and give users only the permissions they need for their role. Microsoft also recommends having emergency access accounts for organisations that need them.

Review your admin list regularly. If someone no longer needs administrator access, their permissions should be changed.

This is an area where managed IT solutions can be useful, particularly for businesses without an internal IT team.

3. Check Your Email Protection

Email remains one of the most common ways that phishing attempts and malicious files reach employees.

Microsoft 365 includes built-in anti-spam, anti-malware and anti-phishing protection. Businesses should check that these protections are active and review the available policies for their subscription. Microsoft 365 Business Premium also provides additional Defender for Office 365 features, including Safe Links and Safe Attachments.

Staff awareness is important too. Employees should know how to spot suspicious messages, unexpected attachments and requests for passwords or payments.

4. Review User Access and Permissions

Not every employee needs access to every business file or Microsoft 365 service.

Review which users can access shared folders, SharePoint sites, OneDrive content and other company resources. When employees change roles, their access should be updated rather than leaving old permissions in place.

Keeping access appropriate for each person’s role reduces the amount of company information available through a compromised account.

Regular permission reviews can form part of a managed IT support contract, particularly when a business has several users and regularly changes its staff or systems.

5. Check Security Defaults or Conditional Access

Microsoft 365 offers security defaults as a basic security baseline. These settings can help protect organisations against common identity-related attacks by requiring MFA and blocking certain older authentication methods.

Businesses using Microsoft Entra ID P1 or P2 may have access to Conditional Access, which provides more control over how and when users can access company resources.

The right option depends on your Microsoft 365 subscription and business requirements, so avoid changing security policies without first understanding how they affect your users and applications.

6. Keep Devices and Applications Up to Date

Microsoft 365 security is not only about account settings. The computers and mobile devices employees use to access company information also matter.

Outdated operating systems, browsers and applications can create security weaknesses. Businesses should have a regular process for applying updates and checking that supported devices are being used.

Microsoft 365 Business Premium also includes additional device security capabilities through Microsoft Intune and related services.

For small businesses, regular maintenance can be easier when included within IT maintenance contracts, rather than relying on employees to remember every update themselves.

7. Review Your Microsoft 365 Setup Regularly

Security settings should not be treated as a one-time task. Your business changes over time. New employees join, old accounts are removed, software changes and Microsoft introduces new features.

A regular review can help identify outdated accounts, unnecessary permissions, missing security controls and settings that no longer match the way your business operates.

This is particularly useful when Microsoft 365 has been set up several years ago and different people have made changes over time.

When Should a Small Business Review Microsoft 365 Security?

There is no need to wait for a security incident before reviewing your Microsoft 365 environment.

A review is worth considering when:

• A new employee joins or leaves
• Your business changes its Microsoft 365 plan
• You introduce new applications
• Employees start working from different locations
• An account shows suspicious activity
• You have never had a formal security review

Regular checks can help your business stay aware of how Microsoft 365 is configured and where improvements may be needed.

Getting More From Microsoft 365

Microsoft 365 can provide much more than business email and document storage. Tools such as Teams, SharePoint, OneDrive, Planner and Power Automate can support communication and everyday workflows when they are set up properly. Brighouse Computer Centre provides Microsoft 365 consultancy covering setup, user onboarding, licensing, training, security settings and ongoing support.

For small businesses, getting the security basics right is a sensible starting point. Reviewing MFA, administrator access, email protection, permissions, security policies and device updates can reduce avoidable risks and help staff use Microsoft 365 with greater confidence.

If your business needs help reviewing its Microsoft 365 environment, Brighouse Computer Centre can provide practical support tailored to your business requirements.

Frequently Asked Questions