Slack vs Microsoft Teams UK 2026: Which Is Better for Your Small Business?

Affiliate disclosure: This article contains affiliate links — if you purchase through them, we may earn a commission at no extra cost to you.

Introduction

If you’re trying to decide between Slack and Microsoft Teams for your small business, you’re not alone. It’s one of the most common questions we get from UK sole traders and small business owners, and the honest answer is: it depends — but not on what most comparison articles will tell you.

The real deciding factor isn’t which tool has more features. It’s whether you already pay for Microsoft 365. That single detail changes the cost calculation completely, and it’s what this article is built around.

We’ll walk you through pricing in pounds, ease of use, integrations, and the kind of business each tool genuinely suits. By the end, you’ll have a clear answer — no fluff, no fence-sitting.

Slack vs Microsoft Teams at a Glance

	Slack	Microsoft Teams
Free plan	Yes (limited)	Yes (limited)
Starting paid price	~£5.75/user/month (Pro)	£3.40 (Teams Essentials) / £5.40 in M365 Business Basic
Bundled with Microsoft 365	No	Yes
Best for	Focused messaging & integrations	Businesses already using Microsoft 365
Video calling	Yes	Yes (stronger)
AI in the plan price	Tiered (full suite on Business+)	Limited; full Copilot is a paid add-on
UK GDPR compliance	Yes	Yes

Pricing: The Number That Actually Matters

Slack Pricing in the UK (2026)

Slack offers three main paid plans for small businesses (prices shown are the annual-billing rate; monthly billing costs more):

• Pro: around £5.75 per user/month (£7 month-to-month)
• Business+: around £11.80 per user/month (£14.40 month-to-month)
• Enterprise+ (formerly Enterprise Grid): custom pricing

The free plan gives you 90 days of message history, one-to-one video calls, and up to 10 integrations. For a very small team just getting started, it can be enough — but you’ll hit the limits quickly.

For a five-person team on the Pro plan, you’re looking at roughly £28.75/month or £345/year. That’s a meaningful line item for a small business budget.

Microsoft Teams Pricing in the UK (2026)

Here’s where it gets interesting. Teams is available standalone, but Microsoft really wants you in the Microsoft 365 ecosystem. Your options look something like this (all annual, excluding VAT):

• Microsoft Teams Essentials: £3.40/user/month — Teams only (chat and meetings), with no Exchange email or Office apps
• Microsoft 365 Business Basic: £5.40/user/month (with Teams) — Teams plus Exchange email, SharePoint, OneDrive, and web versions of the Office apps
• Microsoft 365 Business Standard: around £11.50/user/month — adds the full desktop Office apps (Word, Excel, PowerPoint, etc.)

If you’re already paying for Microsoft 365 Business Basic or Standard, Teams is effectively included at no extra cost. For a five-person team on Business Basic, you’re paying £27/month — and you get email hosting, cloud storage, and Teams all in one. (Following a 2024 competition ruling, Microsoft also sells a Teams-free version of Business Basic at £4.20/user/month, so check which one you’re buying.)

The bottom line on pricing: If your business already uses Microsoft 365, Teams wins on cost without even trying. Even if you’re starting fresh, Business Basic at £5.40 undercuts Slack’s £5.75 Pro plan and throws in email, storage, and Office — while Slack Pro is messaging only. Slack’s plans are competitive for what they are, but they’re rarely the cheaper option once you account for everything Microsoft bundles in.

Features: What You Actually Get Day to Day

Messaging and Channels

Both tools use a channels-based approach to organising conversations, but they feel quite different in practice.

Slack is built around messaging first. Channels are clean and easy to navigate, threads work well, and the search function is excellent — particularly on paid plans where full history is available. If your team lives in the chat, Slack tends to feel more natural and less cluttered.

Microsoft Teams puts messaging alongside video, files, and calendar in one interface. It’s more powerful in terms of what it packs in, but that can also make it feel busier and harder to navigate, especially for new users. The learning curve is steeper, and the interface has historically drawn complaints — though Microsoft has made genuine improvements over the past couple of years.

Video Calls and Meetings

Teams is the stronger option here, full stop. It was built with meetings in mind, and it shows. You get:

• Large group meetings (up to 300 participants)
• Breakout rooms
• Meeting recordings saved to SharePoint or OneDrive
• Deep calendar integration with Outlook
• Transcription and live captions

Slack’s video calling (huddles) has improved significantly, but it still feels secondary to the messaging experience. If your team does a lot of client calls or internal meetings, Teams has the edge.

File Sharing and Storage

Teams integrates directly with OneDrive and SharePoint, meaning files shared in a channel are stored in a proper document management system — versioning, permissions, and all. For small businesses handling lots of documents, this is genuinely useful.

Slack stores files too, but without the depth of SharePoint’s document management. On the free plan, file storage is limited to 5 GB.

Integrations and Third-Party Apps

Slack is widely regarded as the more flexible integration platform. It connects with thousands of third-party tools — project management apps like Trello, Asana and Notion, CRMs, accounting software and more. The Workflow Builder lets non-technical users automate simple tasks without writing code.

Teams also has a strong app marketplace, and it integrates well with the rest of the Microsoft ecosystem. But if your business uses a mixed stack of tools from different vendors, Slack’s integrations tend to be deeper and easier to set up.

AI Features

Both platforms now include AI, but they’ve taken different routes. Slack bundles AI into its plans — the Pro tier gets basic AI (conversation summaries), while the full suite (AI search, daily recaps, file summaries, and the new Slackbot personal AI agent) sits on Business+. Microsoft, by contrast, keeps its full Copilot AI as a paid add-on: base Microsoft 365 plans include only a limited free Copilot Chat, and the in-app Copilot that summarises Teams meetings costs around £13.80/user/month extra (the Copilot Business add-on). So if AI matters to you, factor in that Slack includes more of it in the plan price, while Teams’ best AI is a separate line item.

Security and Compliance

Both platforms meet UK GDPR requirements and offer enterprise-grade security features on paid plans. Microsoft Teams, particularly when used through a Microsoft 365 business subscription, gives IT administrators granular control over data residency, compliance policies, and access management — which may matter more to regulated industries or businesses with strict data requirements.

Slack also offers solid security, including enterprise key management on higher tiers, but Microsoft’s compliance toolset is broader.

Ease of Use: Which Tool Will Your Team Actually Use?

This is often overlooked in feature comparisons, but it matters enormously for small businesses without a dedicated IT person.

Slack is generally faster to get started with. You can invite your team, set up a few channels, and be messaging within an hour. The interface is intuitive, notifications are manageable, and there’s less initial configuration needed.

Microsoft Teams takes longer to feel comfortable with. The interface combines chat, meetings, files, and apps in a way that can feel overwhelming at first. That said, if your team is already familiar with Microsoft products — Outlook, Word, SharePoint — Teams starts to feel like a natural extension of what they already use.

For a very small team or sole trader working with freelancers, Slack’s simplicity is a genuine advantage. For a team already embedded in the Microsoft ecosystem, the short-term learning curve of Teams pays off quickly.

Which Industries and Business Types Suit Each Tool?

Slack Works Well For:

• Tech startups and digital agencies
• Remote-first small teams with varied tool stacks
• Businesses that prioritise flexibility and third-party integrations
• Teams where messaging is the primary communication style

Microsoft Teams Works Well For:

• Small businesses already subscribed to Microsoft 365
• Professional services firms (accountants, solicitors, consultants) who use Outlook and Office daily
• Businesses that need strong video conferencing and document collaboration
• Teams that need compliance and admin controls without extra spend

The Free Plans: Are They Worth It?

Both offer free plans, and both are genuinely useful for very small setups — with caveats.

Slack Free limits you to 90 days of message history, one-to-one calls only, and 10 integrations. Once your team grows or your history becomes important for reference, you’ll feel the walls closing in.

Microsoft Teams Free offers unlimited chat and search history, group video calls (capped at 60 minutes), and around 5 GB of cloud storage. It’s arguably the more generous free tier for a small team that just needs to communicate — the unlimited history alone is a real advantage over Slack’s 90-day cap — though it lacks the Office app integrations you get with a paid Microsoft 365 subscription.

If you’re genuinely undecided and want to test both, starting with the free plans is the sensible move. Just be aware that switching later can be disruptive, so it’s worth thinking ahead about where you want to land.

FAQ

Is Microsoft Teams free with Microsoft 365?

Yes — if you’re on a Microsoft 365 Business Basic, Business Standard or Business Premium subscription, Teams is included at no additional cost. Given that Business Basic starts at £5.40/user/month (with Teams) and also includes Exchange email, OneDrive, and SharePoint, it represents strong value for small businesses already in the Microsoft ecosystem.

Can I use Slack and Microsoft Teams together?

Technically yes — some businesses use both, typically Slack for internal messaging and Teams for client-facing meetings, or vice versa. However, for most small businesses, paying for two communication tools is unnecessary overhead. The integrations between the two platforms have improved, but running parallel tools tends to create confusion rather than solve it.

Which is more secure for UK small businesses?

Both platforms comply with UK GDPR and offer strong security on paid plans. Microsoft Teams, when used as part of a Microsoft 365 subscription, provides more comprehensive compliance and data governance controls, which may be relevant if you’re in a regulated industry. For most small businesses, either platform offers sufficient security on their standard paid tiers.

Does Slack integrate with HMRC’s Making Tax Digital tools?

Slack doesn’t have a direct integration with HMRC or Making Tax Digital platforms, but it does integrate with many UK accounting tools — including Xero, QuickBooks and FreeAgent — that handle MTD compliance. You can set up notifications for invoice reminders or payment alerts within Slack channels, which many small business owners find useful for staying on top of their finances.

Conclusion: Our Honest Recommendation

Here’s the straight answer:

If you already pay for Microsoft 365, use Teams. There’s no rational justification for paying separately for Slack when a capable messaging and video platform is already bundled into your subscription. Teams has improved considerably, and for most small businesses doing a reasonable amount of document collaboration and video calls, it does the job well.

If you don’t use Microsoft 365 and you’re choosing a standalone tool, Slack is the better experience — particularly if your team is tech-comfortable, uses a range of third-party apps, and prioritises clean, focused communication. The Pro plan at around £5.75/user/month is competitive for what it offers, though it’s worth weighing that cost against the total value of a Microsoft 365 subscription.

For sole traders and very small teams on a tight budget, the Teams free plan edges ahead on generosity, and the jump to Microsoft 365 Business Basic at £5.40/user/month makes compelling sense if you need email hosting anyway.

The honest truth is that both tools will do the job. The right choice comes down to your existing software stack, your budget, and how your team prefers to work — not which one has the longer feature list.

Pricing and features correct at time of writing. Plans and capabilities are subject to change — always confirm current details on the provider’s website before purchasing.