Microsoft 365 Licensing for Irish SMEs – What You Actually Need

Microsoft 365 has been around since 2011. In the early days, it was straightforward — you moved your email from an on-premises Exchange server to the cloud, and that was the product. Fifteen years later, it has grown into a sprawling ecosystem of productivity tools, security features, compliance capabilities, and collaboration platforms. The licensing has grown to match.

The Microsoft commercial price list runs to approximately 9,000 line items. That is not a typo. For an Irish SME without a dedicated IT team, working out which licence you actually need — and whether you are already paying for capabilities you do not realise you have — is genuinely difficult.

This guide focuses on the practical question: which Microsoft 365 licence should most Irish SMEs be using, and why?

The problem with Microsoft licensing

Three things have made Microsoft licensing confusing for SMEs.

Constant renaming and repackaging. Products get renamed, merged, split, and repositioned regularly. Office 365 became Microsoft 365. Azure AD became Entra ID. Defender for Endpoint changed names and tiers multiple times. If you set up your licensing three years ago and have not revisited it, the product names in your admin portal may not match anything in the current price list.

Over-licensing. Without someone tracking what each licence includes, businesses frequently purchase standalone products that are already bundled into their existing subscription. I regularly see organisations paying separately for email filtering, backup, or endpoint protection that is already included in the Microsoft 365 licence they have — they just never activated it.

Under-licensing. The opposite problem is equally common. A business buys the cheapest licence that gets them email and Office apps, not realising it lacks security features they actually need. They end up with no endpoint protection, no Conditional Access, no device management — and bolting these on separately almost always costs more than upgrading to a licence that includes them.

What this guide does not cover

To keep this practical, I am deliberately narrowing the scope. This guide does not cover:

• Dynamics 365 or Business Central — separate product families with their own licensing models
• Power BI Pro or Premium — worth a separate discussion for data-heavy organisations
• Perpetual server licences — relevant for on-premises infrastructure but a different conversation
• Edge cases — shared mailboxes, auto-attendants, call queues, resource accounts. These are important but specific enough that they need case-by-case guidance.

What this guide does cover is the core Microsoft 365 licensing decision that every Irish SME needs to get right.

The three approaches

There are three ways to approach Microsoft 365 licensing. Each has its place.

A la carte: picking individual products

You can buy individual Microsoft products separately — Exchange Online for email, Microsoft Defender for Endpoint for security, Intune for device management, and so on. Each is available as a standalone SKU.

When this makes sense: Almost never for an SME. A la carte pricing exists for organisations with very specific, narrow requirements — perhaps they only need email and nothing else, or they have existing security tooling and only want one Microsoft component. In practice, buying three or four standalone products quickly exceeds the cost of a bundle that includes all of them plus more.

The risk: You end up with coverage gaps. Standalone products do not always integrate as tightly as bundled ones, and you miss capabilities you did not know were available.

The SME recommendation: Microsoft 365 Business Premium

For the majority of Irish SMEs with up to 300 users, Microsoft 365 Business Premium is the right licence. It is the most complete bundle Microsoft offers for small and medium businesses, and it covers the full spectrum of what most organisations need.

Here is what Business Premium includes:

Productivity and collaboration:

• Exchange Online with 50 GB mailbox per user
• OneDrive for Business with up to 5 TB storage
• Microsoft Office apps (Word, Excel, PowerPoint, Outlook, Teams) installed on up to 5 desktops and 5 mobile devices per user
• SharePoint Online for document management and intranet
• Microsoft Teams for chat, meetings, and collaboration

Security:

• Microsoft Defender for Endpoint (Plan 1) — endpoint detection and response, not just antivirus
• Microsoft Defender for Office 365 (Plan 1) — Safe Links, Safe Attachments, and advanced anti-phishing
• Azure Information Protection (Plan 1) — data classification and labelling
• Conditional Access — policies that control when, where, and how users can sign in
• Multi-factor authentication enforcement

Device management:

• Microsoft Intune — full device management for Windows, macOS, iOS, and Android
• Autopilot — zero-touch device provisioning for new hires
• Remote wipe for lost or stolen devices

Compliance:

• Data Loss Prevention (DLP) — prevent accidental sharing of sensitive information
• eDiscovery — search across mailboxes and files for compliance or legal requests
• Retention policies — define how long data is kept and when it is deleted

The critical point for Irish SMEs: Business Premium includes Defender for Endpoint, Conditional Access, and Intune. These are not nice-to-haves — they are foundational security controls that are increasingly required by regulation (NIS2, GDPR), by cyber insurance policies, and by client due diligence questionnaires. Buying a cheaper licence and then bolting these on separately costs more and creates integration gaps.

Enterprise licensing: E3 and E5

Microsoft 365 Enterprise licences (E3 and E5) exist for larger organisations with more complex requirements. There is no hard user-count cutoff — Business Premium supports up to 300 users, but some organisations switch to Enterprise earlier because they need specific capabilities.

E3 adds (over Business Premium):

• Unlimited email archiving
• Azure Information Protection Plan 2
• Enhanced DLP capabilities
• No 300-user limit
• Windows 11 Enterprise licensing

E5 adds (over E3):

• Microsoft Defender for Endpoint Plan 2 (advanced hunting, automated investigation)
• Microsoft Defender for Office 365 Plan 2 (attack simulation, threat explorer)
• Microsoft Sentinel integration points
• Phone System (cloud PBX)
• Advanced compliance tools (insider risk, communication compliance)
• Audio Conferencing

When to consider Enterprise: If you have a dedicated IT team, specific compliance or audit requirements (PCI-DSS, ISO 27001), or need advanced security capabilities like threat hunting, attack simulation, or SIEM integration. For most Irish SMEs under 300 users, Business Premium covers the ground.

Voice calling: the missing piece

One area where Microsoft 365 Business Premium does not provide a complete solution out of the box is voice calling. Teams includes chat, video meetings, and screen sharing, but making and receiving traditional phone calls requires an add-on.

Microsoft Teams Phone with Calling Plan adds:

• A phone number assigned to each licensed user
• Inbound and outbound PSTN calling (landlines and mobiles)
• Call queues, auto-attendants, and voicemail
• Call forwarding and simultaneous ring

This is a per-user add-on to Business Premium. For many SMEs, it replaces a separate phone system entirely — no more PBX hardware, no more separate phone contracts, no more desk phones (unless you want them). Calls route through Teams on the user’s laptop, phone, or a dedicated Teams device.

The economics are usually favourable. Replacing a traditional phone system with Teams Phone eliminates the hardware maintenance, the separate contracts, and the management overhead. The per-user cost is predictable and scales with your headcount.

The decision in practice

For an Irish SME evaluating Microsoft 365 licensing, the practical decision tree looks like this:

Start with Microsoft 365 Business Premium. This is the default recommendation for businesses with up to 300 users. It includes email, productivity apps, security (endpoint protection, email filtering, Conditional Access), device management, and compliance tools in a single per-user licence.

Add Teams Phone with Calling Plan if you want to consolidate voice calling into Teams. This replaces a separate phone system and gives every user a direct number.

Consider Enterprise (E3/E5) only if you have specific needs that Business Premium does not cover: unlimited archiving, advanced threat hunting, attack simulation, or compliance tools for regulated industries. If you are not sure whether you need Enterprise features, you almost certainly do not — yet.

Avoid a la carte unless you have a genuinely narrow requirement. Buying individual products seems cheaper per line item but adds up quickly, and you miss the integration benefits of the bundle.

Common mistakes I see

Having reviewed licensing across dozens of SME environments, these are the patterns that come up repeatedly:

Paying for third-party email filtering when Defender for Office 365 is included. Business Premium includes Safe Links, Safe Attachments, and advanced anti-phishing. Many organisations are paying a separate vendor for capabilities they already have.

No device management despite having Intune. Intune is included in Business Premium, but many organisations have never enabled it. Their devices are unmanaged — no compliance policies, no encryption enforcement, no ability to remote wipe.

Running Business Basic or Standard when security requirements demand Premium. Business Basic and Business Standard are cheaper, but they lack Defender for Endpoint, Conditional Access, and Intune. For any organisation that handles sensitive data, faces compliance requirements, or has a cyber insurance policy, these are not optional.

Mixed licensing with no clear rationale. Some users on Basic, some on Standard, some on Premium, often with no documented reason for the variation. This creates inconsistent security coverage and makes administration more complex than it needs to be.

How to check what you have

If you are an existing Microsoft 365 customer and are unsure what licences your organisation is using:

1. Sign in to the Microsoft 365 admin centre at admin.microsoft.com
2. Go to Billing > Licences
3. Review the licence types and the number assigned versus purchased

This gives you the raw facts. What it does not tell you is whether the features included in those licences are actually enabled and configured. Having Business Premium but never setting up Conditional Access or Intune means you are paying for security capabilities you are not using.

The bottom line

Microsoft 365 licensing does not need to be as complicated as it appears. For the majority of Irish SMEs, the answer is Microsoft 365 Business Premium — it covers productivity, security, device management, and compliance in a single bundle, at a per-user cost that is significantly less than the alternatives when purchased separately.

The licence itself is only half the equation. What matters equally is whether the features included in that licence are actually deployed and configured. A Business Premium licence with Defender, Conditional Access, and Intune properly set up is a fundamentally different security posture than the same licence sitting unused. The licensing decision gets you the tools — the configuration is what makes them effective.