Microsoft 365 Plans Explained: Which One Does Your Business Need?

Microsoft 365 has become the standard productivity platform for businesses across the United Kingdom. From email and document creation to video conferencing and cloud storage, it provides the tools that most businesses rely on every single day. But choosing the right Microsoft 365 plan is not straightforward. Microsoft offers a bewildering array of options — Business Basic, Business Standard, Business Premium, E3, E5, F1, F3, and more — each with different features, limitations, and price points.

Choosing the wrong plan costs your business money. Pay for features you do not use and you waste budget. Choose a plan that is too basic and your team lacks essential tools, leading to workarounds, shadow IT, and security gaps. This guide cuts through the complexity and explains exactly which Microsoft 365 plan is right for your UK business.

Understanding the full Microsoft 365 ecosystem requires looking beyond the surface-level feature comparisons. Microsoft has restructured its licensing multiple times over the past decade, and the current naming conventions — which dropped the "Office 365" branding in favour of "Microsoft 365" — still cause confusion. The practical difference matters: Microsoft 365 plans include Windows licensing and advanced security features that the older Office 365 plans did not. If your organisation is still running legacy Office 365 licences, it is worth reviewing whether a migration to the current Microsoft 365 plans would deliver better value and stronger security.

The Microsoft 365 Business Plans

For UK SMEs with up to 300 users, Microsoft offers three main business plans. Each includes Exchange Online email with a custom domain, Microsoft Teams for chat and video conferencing, and OneDrive cloud storage. The differences lie in the desktop applications, security features, and advanced capabilities.

Microsoft 365 Business Basic

Business Basic is the entry-level plan and provides web and mobile versions of the Office applications (Word, Excel, PowerPoint, Outlook) along with Exchange Online email, Teams, OneDrive with 1 TB of storage per user, and SharePoint Online. Critically, it does not include the desktop versions of the Office applications — your team can only use Office through a web browser or mobile app.

This plan suits businesses where staff primarily use email, Teams, and basic document editing, and where the web-based versions of Office are sufficient. However, if your team regularly works with complex spreadsheets, lengthy documents, or needs offline access, the web versions will feel limited.

In practical terms, the web-based versions of Excel lack support for advanced features such as Power Query, complex macros, and large dataset handling. Word for the web does not support advanced formatting, mail merge, or certain referencing tools. If your finance team builds detailed forecasting models, your HR department produces formatted policy documents, or your sales team creates polished client proposals, the web applications will prove inadequate. However, for organisations where email, Teams meetings, and light document editing constitute the bulk of daily work — such as many professional services firms, logistics companies, or retail operations — Business Basic can be a cost-effective foundation.

Microsoft 365 Business Standard

Business Standard includes everything in Business Basic plus the full desktop versions of Word, Excel, PowerPoint, Outlook, and OneNote, installable on up to five PCs or Macs per user. It also includes Microsoft Bookings for appointment scheduling and the ability to host webinars in Teams.

This is the most popular plan for UK SMEs and for good reason. The desktop Office applications are significantly more capable than the web versions, and for most knowledge workers, they are essential tools. If your team uses Office applications daily, Business Standard should be your starting point.

Beyond the desktop applications, Business Standard unlocks several collaboration features that make it particularly valuable for growing teams. Microsoft Loop provides a collaborative workspace similar to Notion, allowing teams to co-author documents and track projects in real time. The plan also includes Microsoft Forms for surveys and data collection, Microsoft Lists for structured information tracking, and Sway for creating interactive presentations and reports. For UK businesses that want a comprehensive productivity toolkit without the complexity and cost of the Premium tier, Business Standard covers the vast majority of day-to-day requirements.

One aspect that catches many businesses off guard is the installation limit. Each user can install the desktop Office applications on up to five PCs or Macs and five mobile devices simultaneously. For organisations where staff use both a desktop in the office and a laptop at home, this generous allowance ensures everyone has access to the full suite wherever they work — a particularly relevant consideration given the continued prevalence of hybrid working arrangements across the UK.

Microsoft 365 Business Premium

Business Premium includes everything in Business Standard plus a comprehensive suite of security and device management features: Intune for mobile device management, Azure Information Protection for data classification and encryption, Azure AD Premium P1 for conditional access and multi-factor authentication, and Microsoft Defender for Business for advanced endpoint protection.

For any business that handles sensitive data, is subject to regulatory requirements, or wants enterprise-grade security without enterprise-grade costs, Business Premium is the plan we recommend. The security features alone would cost more than the price difference if purchased separately.

To put this into perspective, Intune alone would cost approximately £6.50 per user per month as a standalone add-on, and Microsoft Defender for Business is priced at around £2.50 per user per month separately. When you add Azure AD Premium P1 and Azure Information Protection, the combined cost of these security components exceeds the price difference between Standard and Premium. For any UK business operating in a regulated sector — financial services, healthcare, legal, or accountancy — Business Premium should be considered the minimum acceptable plan rather than a premium upgrade.

The device management capabilities in Business Premium deserve particular attention. With Intune, you can enforce encryption on all company devices, remotely wipe lost or stolen laptops, push security policies to mobile phones accessing company email, and ensure that only compliant devices can connect to your organisation's data. For businesses with staff working from home or travelling frequently, these controls are not optional luxuries — they are essential safeguards against data breaches that could result in significant fines under UK GDPR.

Feature	Business Basic	Business Standard	Business Premium
Price per user/month (exc. VAT)	£4.60	£9.40	£16.60
Web & mobile Office apps	Yes	Yes	Yes
Desktop Office apps	No	Yes	Yes
Exchange Online email	50 GB mailbox	50 GB mailbox	50 GB mailbox
OneDrive storage	1 TB per user	1 TB per user	1 TB per user
Microsoft Teams	Yes	Yes	Yes
SharePoint Online	Yes	Yes	Yes
Intune device management	No	No	Yes
Advanced threat protection	No	No	Yes
Conditional access	No	No	Yes
Max users	300	300	300

The Enterprise Plans: E3 and E5

For businesses with more than 300 users, or those needing advanced capabilities not available in the Business plans, Microsoft offers Enterprise plans. The two most relevant are E3 and E5.

Microsoft 365 E3

E3 includes the full desktop Office suite, Exchange Online with 100 GB mailboxes (double the Business plans), unlimited OneDrive storage, Azure AD Premium P1, Azure Information Protection P1, and advanced compliance tools including eDiscovery and data loss prevention (DLP). It is the enterprise equivalent of Business Premium but with larger mailboxes, more compliance tools, and no user limit.

E3 also includes advanced compliance capabilities that are increasingly important for UK organisations. Data loss prevention policies can automatically detect and protect sensitive information such as National Insurance numbers, bank account details, and passport numbers, preventing them from being shared inappropriately via email or documents. eDiscovery tools allow legal and compliance teams to search across mailboxes, SharePoint sites, and Teams conversations to respond to regulatory requests or legal proceedings. For organisations in regulated industries — financial services, healthcare, legal, or accountancy — these compliance tools are often a regulatory requirement rather than a luxury.

The upgrade from 50 GB to 100 GB mailboxes may seem like a minor technical detail, but for organisations with staff who handle large volumes of email — particularly those in professional services, sales, or client-facing roles — it eliminates the constant battle against mailbox size limits that plagues users on Business plans. Combined with unlimited OneDrive storage, E3 removes storage constraints entirely, allowing your team to focus on productive work rather than managing their available space.

Microsoft 365 E5

E5 is the most comprehensive plan, adding advanced security features (Microsoft Defender for Endpoint P2, Cloud App Security), advanced compliance (Advanced eDiscovery, insider risk management), Power BI Pro for business intelligence, and a full cloud phone system. It is a significant investment but provides everything a large organisation needs in a single licence.

The inclusion of Power BI Pro in E5 is particularly noteworthy for data-driven organisations. Power BI transforms raw data from across your business systems into interactive dashboards and reports, enabling management to make informed decisions based on real-time information rather than gut instinct. When purchased separately, Power BI Pro costs approximately £7.50 per user per month — a significant expense if deployed across an entire management team. Having it bundled into E5 provides compelling value.

The cloud phone system in E5, Microsoft Teams Phone, replaces traditional PBX telephone systems entirely. Staff can make and receive calls using their regular phone number directly through the Teams application on their computer, mobile phone, or a desk phone. For UK businesses with multiple offices or remote workers, this eliminates the need for separate telephone systems at each location and provides a unified communication experience. Combined with auto-attendants and call queues, E5 can replace telephone systems that would otherwise cost thousands of pounds per year to maintain.

Microsoft Defender for Endpoint P2, included in E5, provides the most advanced endpoint security available in the Microsoft ecosystem. It includes automated investigation and remediation capabilities that can detect, contain, and resolve threats without human intervention, as well as threat analytics that provide intelligence about emerging attack campaigns targeting UK organisations. For larger businesses or those in high-risk sectors, this level of automated threat response significantly reduces the burden on internal IT teams.

Monthly per-user pricing (excluding VAT) as of March 2026

Which Plan Should Your Business Choose?

With so many options, how do you decide? Here is our practical decision framework based on years of helping UK SMEs choose the right plan.

Choose Business Standard if your team needs the full desktop Office applications for daily work. This is the sweet spot for most UK SMEs with 10 to 200 employees who need professional productivity tools but do not have complex security or compliance requirements.

Choose Business Premium if you handle sensitive data (financial, medical, legal, personal), need to manage company devices, require conditional access policies, or want advanced email threat protection. For any business concerned about cyber security — which should be every business — the security features in Business Premium are genuinely valuable.

Choose E3 or E5 if you have more than 300 users, need advanced compliance tools, require 100 GB mailboxes, or need unlimited OneDrive storage. E5 is justified for organisations that need built-in phone system capabilities, advanced analytics with Power BI, or the highest tier of security and compliance tools.

Assessing Your Organisation's Needs

Before committing to a plan, conduct a practical assessment of how your team actually works. Spend a week observing which applications each department uses daily, which features they rely on, and where they encounter limitations with existing tools. This exercise often reveals surprising insights — the marketing team may need advanced PowerPoint capabilities that only come with desktop apps, while the warehouse team may only ever check email on their phones. Armed with this data, you can make an evidence-based licensing decision rather than guessing or defaulting to the most expensive option.

Consider also your organisation's growth trajectory. If you plan to hire significantly over the next two to three years, factor in the licensing cost at scale. A business choosing between Business Standard and Business Premium for 20 users faces a cost difference of approximately £1,700 per year. For 100 users, that difference grows to £8,600 per year. At that scale, the decision warrants careful analysis of whether the additional security features in Premium are genuinely needed for every user, or whether a mixed licensing approach would be more appropriate.

Mixing Licence Types

One often overlooked strategy is mixing licence types within your organisation. Not every employee needs the same plan. Your finance team might need Business Premium for its security and compliance features, while reception staff might only need Business Basic for email and Teams. Frontline workers might need F1 or F3 licences, which are significantly cheaper.

Microsoft allows you to mix and match plans within the same tenant, so you can optimise your spending by assigning the right licence to each role. A business with 50 users might have 5 on Business Basic, 35 on Business Standard, and 10 on Business Premium — saving hundreds of pounds per month compared to putting everyone on Premium.

To implement a mixed licensing strategy effectively, start by categorising your staff into role-based groups. Executive and management roles typically need Business Standard or Premium for full Office applications and, where applicable, advanced security features. Administrative and office-based staff generally need Business Standard for the desktop applications they use daily. Customer-facing or frontline staff who primarily use email and Teams can often work effectively with Business Basic. Seasonal or temporary workers may only need Business Basic for the duration of their engagement.

Document your licensing decisions in a simple matrix that maps job roles to licence types. This becomes invaluable when onboarding new staff, as it removes guesswork about which licence to assign. Review the matrix quarterly alongside your licence audit to ensure it still reflects the actual needs of each role. As your organisation evolves and staff responsibilities change, the appropriate licence type may change with them. A receptionist who takes on marketing responsibilities, for instance, will likely need upgrading from Basic to Standard to access the desktop design and publishing tools.

Key Add-Ons to Consider

Beyond the core plans, Microsoft offers a range of add-ons that can enhance your Microsoft 365 environment. The most relevant for UK SMEs include Microsoft Copilot for AI-powered assistance across all Office applications, Microsoft Teams Phone for replacing your traditional phone system, Power BI Pro for advanced business intelligence and reporting, and Visio for flowcharts and diagrams.

Add-ons are charged per user per month on top of your base plan. Before purchasing add-ons, check whether the feature you need is already included in a higher-tier plan — sometimes upgrading the base plan is more cost-effective than adding individual components.

Microsoft Copilot: The AI Question

Microsoft Copilot is the most significant addition to the Microsoft 365 ecosystem in recent years. Powered by large language models, Copilot integrates directly into Word, Excel, PowerPoint, Outlook, and Teams, offering AI-powered assistance for drafting documents, summarising emails, analysing data, creating presentations, and generating meeting notes. For UK businesses, Copilot can dramatically reduce the time spent on routine tasks — drafting client proposals, summarising lengthy email threads, or creating first drafts of reports.

Copilot is available as an add-on at £25 per user per month, which is a substantial investment. Not every employee will benefit equally. Focus deployment on roles where document creation and data analysis consume significant time — typically management, professional services staff, marketing teams, and executive assistants. Start with a pilot group of 5 to 10 users, measure the productivity impact over three months, and then expand based on the results. This measured approach ensures you invest in Copilot where it delivers genuine return on investment rather than deploying it broadly as an expensive novelty.

Teams Phone: Replacing Your Phone System

Microsoft Teams Phone deserves special attention for UK businesses still running traditional telephone systems. The add-on — or its inclusion in E5 — allows you to route incoming and outgoing calls through Teams using your existing phone numbers. This means staff can answer business calls on their laptop, mobile phone, or a Teams-compatible desk phone, regardless of whether they are in the office, at home, or travelling. For UK businesses with multiple sites, Teams Phone eliminates the need for separate PBX systems at each location and consolidates your entire telephony infrastructure into a single platform.

Migration and Setup Considerations

Choosing the right plan is only half the challenge. Migrating your existing email, files, and settings to Microsoft 365 requires careful planning and execution. Common migration scenarios include moving from on-premises Exchange Server, migrating from Google Workspace, transitioning from POP/IMAP email hosting, and consolidating multiple domains.

Each scenario has its own complexities, and a poorly executed migration can result in lost emails, broken calendars, missing contacts, and days of disruption. Professional migration services — such as those offered by managed IT providers — ensure a smooth transition with minimal impact on your team.

Planning Your Migration

A successful Microsoft 365 migration begins with thorough planning well before any data is moved. Start by auditing your current environment: how many mailboxes need to be migrated, how much data is in each mailbox, what shared calendars and contacts exist, what distribution lists are in use, and what integrations currently connect to your email system. This audit determines the migration approach, timeline, and potential complications.

For UK businesses migrating from on-premises Exchange Server, the migration can typically be performed in stages — starting with a hybrid configuration that allows both systems to coexist during the transition period. This approach minimises disruption because staff can continue working normally while mailboxes are migrated in batches, typically during evenings or weekends. The entire process usually takes between two and six weeks depending on the number of mailboxes and the volume of data involved.

For businesses migrating from Google Workspace, Microsoft provides dedicated migration tools that transfer email, calendar events, and contacts with reasonable fidelity. However, Google Drive files may require conversion to Microsoft formats, and any Google-specific integrations or automations will need to be recreated using Microsoft equivalents such as Power Automate. Plan for a period of parallel running where both systems are available, giving staff time to familiarise themselves with the Microsoft 365 environment before the old system is decommissioned.

Regardless of your source platform, communicate the migration timeline clearly to all staff at least two weeks in advance. Provide training sessions on the new tools — even experienced users will need guidance on features that differ from their current platform. Designate a small group of tech-savvy staff as internal champions who can provide peer support during the first few weeks after the migration.

Security Configuration Matters

Regardless of which plan you choose, the default security settings in Microsoft 365 are not sufficient for a business environment. At a minimum, you should enable multi-factor authentication for all users, configure email authentication (SPF, DKIM, DMARC) to prevent email spoofing, set up data loss prevention policies for sensitive information, review and restrict external sharing settings in SharePoint and OneDrive, and configure mobile device policies if staff access email on personal phones.

Business Premium and E3/E5 provide the tools to implement these configurations, but they do not configure themselves. Many businesses purchase Premium licences and then never enable the security features they are paying for — arguably the worst possible outcome. If you lack the expertise to configure these settings, work with a managed IT provider who can ensure your Microsoft 365 environment is properly secured.

Essential Security Configurations

Multi-factor authentication is the single most effective security measure you can implement in Microsoft 365. Microsoft reports that MFA prevents over 99.9% of account compromise attacks. Despite this, nearly half of UK businesses have not enabled MFA for all users. Implementing MFA should be the first security action for any new Microsoft 365 deployment, and it is included in every plan at no additional cost. Security defaults — a Microsoft feature that enforces MFA for all users — can be enabled with a single toggle in the Azure portal and provides immediate protection.

Email authentication — specifically SPF, DKIM, and DMARC records — prevents criminals from sending emails that appear to come from your domain. Without these records configured correctly, attackers can send convincing phishing emails to your clients and suppliers that appear to originate from your organisation, potentially damaging your reputation and your relationships. Configuring these records is a technical task that involves updating your DNS settings, but it is a one-time effort that provides permanent protection for your domain's reputation.

Beyond these fundamentals, consider implementing sensitivity labels to classify and protect confidential documents, configuring retention policies to ensure important emails and files are preserved for the legally required period, and setting up alerts for suspicious activity such as impossible travel scenarios — where a user appears to log in from London and then from another country within minutes — or unusual mass file downloads. These configurations turn Microsoft 365 from a basic productivity platform into a genuinely secure business environment that protects your organisation, your clients, and your regulatory standing.