The best AI tools for business: ChatGPT, Claude, Copilot or Gemini?

This guide compares the four AI assistants we teach in our AI training for business: ChatGPT, Claude, Microsoft 365 Copilot and Gemini. There are no affiliate links on this page.

All four can draft, summarise, research and help with a spreadsheet. When you're choosing AI tools for a small business, look at where each one works, what it can see of your files and what the vendor says it does with your data.

Which AI tool is best for a small business?

Start with the software you already pay for. On Microsoft 365, test Copilot first. On Google Workspace, test Gemini first. If you use neither, or a bit of both, try ChatGPT or Claude.

ChatGPT vs Claude vs Copilot vs Gemini at a glance

Checked against the vendors' own pages on 8 October 2026.

The four tools, one by one

ChatGPT

OpenAI's assistant is an all-rounder for drafting, rewriting and thinking a problem through. It runs in its own app and can connect to Google Drive, Outlook, SharePoint, Teams and Slack, among others, to find a file or summarise a document. Which of these you get depends on your plan and region. On ChatGPT Business, many are switched on by default and an admin can turn them off.

Claude

Anthropic's assistant also has its own app, with connectors for Gmail, Google Calendar, Google Drive, Microsoft 365, Slack and HubSpot, among others. Its Projects keep related chats and documents together, and on the Team plan you can share a project with colleagues. The Team plan also includes single sign-on and admin controls over those connectors.

Microsoft 365 Copilot

Copilot works inside the apps your team already has open: drafting emails in Outlook, summarising meetings and capturing action items in Teams, formulas and analysis in Excel. What you get depends on your licence. Copilot Chat, included with eligible Microsoft 365 licences, works mainly from the web and files you give it. The full Microsoft 365 Copilot add-on draws on your emails, files, meetings and calendar for you. Microsoft has also renamed Microsoft 365 Copilot to Microsoft Copilot, so you'll see both names for a while.

Gemini

Google's assistant works inside Gmail, Docs, Sheets, Slides, Drive, Meet and Calendar, and in its own Gemini app. Google says Gemini won't retrieve a document or email that a person doesn't have access to. Which features you get depends on your Workspace plan.

Business plans vs personal accounts

If staff use personal ChatGPT, Claude or Gemini accounts for work, fix that first. The business has no admin control over those accounts, and they run on consumer terms. On ChatGPT's personal plans, such as Plus, OpenAI may use what ChatGPT reads through connected apps to train its models if the "Improve the model for everyone" setting is on.

A business plan puts you in charge of who has access and brings the vendor's business data terms. With Microsoft, staff need to sign in with their work account, not a personal one, for Copilot's enterprise data protection to apply.

If we set a tool up for you, the subscription is in your name, paid from your own account and listed in the quote. How we price has the detail.

What the vendors say about your data

In each vendor's own words:

• OpenAI: "By default, we do not use your business data for training our models." That covers ChatGPT Business and Enterprise.
• Anthropic: "Anthropic may not train models on Customer Content from Services," say its commercial terms.
• Microsoft: "Prompts, responses, and data accessed through Microsoft Graph aren't used to train foundation LLMs, including those used by Microsoft Copilot."
• Google: "Your content is not human reviewed or otherwise used for Generative AI model training outside your domain without permission." That covers qualifying Google Workspace editions.

None of this makes a tool "UK GDPR compliant" on its own. That depends on what you put in and how you use it. Before staff paste in personal details about customers or colleagues, read the vendor's data processing terms. The ICO's guidance on AI and data protection is the official starting point.

How to choose: a one-week test

Run the test on your own work, with the people who'll use the tool.

1. 01

   Shortlist one or two tools

   More than two is hard to compare fairly.

2. 02

   Pick three weekly jobs

   Such as meeting notes, routine replies or a monthly report.

3. 03

   Test for a week

   On a business plan, or with client names and personal details taken out.

4. 04

   Compare on Friday

   Which drafts needed less editing? Which tool would the team keep?

Example: a six-person lettings agency on Microsoft 365 tests Copilot and Claude on inspection notes, the Monday call summary and routine landlord replies, which a person reads before they're sent. On Friday it compares the results and picks one.

Choosing tools is part of our work as an AI consultant for UK SMEs, and every job starts with a free call.

Five mistakes to avoid

1. Leaving staff on personal accounts. Company work belongs on a plan you control.
2. Buying licences for everyone on day one. Start with a few people.
3. Switching on Copilot or Gemini before tidying your sharing settings. Both follow your existing permissions. If everyone can open the payroll folder, the assistant can find it for anyone who asks.
4. Trusting answers without checking. Microsoft's own guidance says generative AI responses "aren't guaranteed to be 100% factual". That goes for all four.
5. Letting AI message customers unchecked. Have a person check AI-drafted messages before they go out, and review live chats and calls afterwards.

Using AI with your customers

Everything above is about your team's own work. AI that talks to customers, on your website or your phone line, needs more care. When we set one up, these rules always apply. Standard messages like booking reminders go out automatically, in wording you've approved. Anything AI writes for one particular customer is checked by a person before it goes out. Live assistants, such as website chats and phone receptionists, always say they're AI, hand over to a person on request, and have their conversations reviewed afterwards. No outbound AI marketing calls. There's more in AI receptionists for business.

Beyond the chat window

A chat assistant helps one person at a time. When a job comes round every day, like chasing unpaid invoices, an automation that joins your tools is often the better fit. What is AI automation? explains the difference, and Zapier vs Make vs n8n compares the tools that connect your apps. For assistants that carry out tasks, see AI agents for business.

If you're still working out where AI fits, start with How can AI help my business? or our free AI readiness assessment for business, which needs no email.