For most small businesses the choice comes down to where your work already lives. If your team spends the day in Outlook, Word, Excel and Teams, start with Microsoft 365 Copilot, because it works inside those apps and uses your company files. If you mostly need a strong assistant for writing, analysis and research, Claude and ChatGPT are both excellent, and the business plans for each cost about the same ($20 to $25 per person per month). Whichever you pick, buy the business version, not personal accounts: the business plans don't train on your data by default and give you admin controls.
What each one is
Microsoft 365 Copilot is Microsoft's assistant built into Word, Excel, PowerPoint, Outlook and Teams. It can read your email, files and meetings (only the ones each person already has access to) and use them to draft, summarize and answer questions. There's also a free Copilot Chat included with eligible Microsoft 365 business plans, which is a web-based assistant without the deep access to your files.
Claude, from Anthropic, is a general-purpose assistant with a reputation for careful writing, long documents and analysis. The Team plan adds shared projects, admin controls and connectors to tools such as Google Drive, Microsoft 365 and Slack.
ChatGPT, from OpenAI, is the most widely used general-purpose assistant. The Business plan (formerly called Team) adds a shared workspace, admin controls, custom GPTs and connectors to other tools.
What they cost on business plans
These are the vendors' US list prices as of September 2026. Prices change often, so check before you buy.
| Microsoft 365 Copilot Business | Claude Team | ChatGPT Business | |
|---|---|---|---|
| Price per person | $21 per month on an annual plan (discounted to $18 through December 31, 2026), or $25.20 month to month | $20 per month billed annually, $25 billed monthly (standard seat) | $20 per month billed annually, $25 billed monthly |
| Minimum | Needs a Microsoft 365 business plan underneath | 2 seats | 2 users |
| Trains on your data by default | No | No | No |
| Free option for business | Copilot Chat, included with eligible Microsoft 365 plans | No | No |
Claude Team also has a premium seat ($100 per month billed annually) with much higher usage limits, useful for one or two heavy users rather than the whole team.
What each is best at
These are general strengths, not hard rules. All three are capable, and all three change every few months.
Copilot is best when the job involves your own Microsoft 365 content: "summarize this email thread," "draft a reply using last quarter's proposal," "what did we decide in yesterday's Teams meeting." Nothing else works inside Outlook and Teams the way it does. For general writing and reasoning outside your files, many people find Claude or ChatGPT stronger.
Claude is a strong pick for long documents and careful writing: contracts, reports, policies, proposals and anything that needs a consistent voice. It handles large files well and tends to follow detailed instructions closely.
ChatGPT is the most flexible all-rounder, with image generation, voice and a large library of custom GPTs. If your team already uses it personally, adoption is easier.
How each handles your data
This is the question most small businesses should ask first.
- Business plans don't train on your data by default. Microsoft states that prompts, responses and data accessed through Microsoft 365 aren't used to train its foundation models. Anthropic says it won't use inputs or outputs from its commercial products (including Claude Team) to train its models by default. OpenAI says the same for ChatGPT Business.
- Personal plans are different. On consumer ChatGPT (Free, Plus, Pro), conversations can be used for training unless the person turns off "Improve the model for everyone" in Settings, then Data controls. On consumer Claude (Free, Pro, Max), users choose whether to allow training. If your staff paste client information into personal accounts, you don't control that setting. That's the main reason to buy business seats.
- Feedback buttons count. On Claude and ChatGPT, giving a thumbs up or down can let the vendor use that conversation for training, even on a business plan. Tell your team.
- Copilot sees what each person can see. It only shows people content they already have access to, but if your SharePoint or OneDrive sharing is loose, Copilot makes that much easier to find. Clean up permissions before you roll it out. We cover this in is Microsoft Copilot safe for client data.
- Regulated data needs more. None of these three business plans, as sold here, is the right home for patient health information. Anthropic offers a HIPAA business associate agreement on Claude Enterprise, OpenAI offers one on specific healthcare and enterprise products, and Microsoft covers Microsoft 365 under its own terms. Confirm with the vendor, and your own advisor, before you put regulated data in any tool.
How to choose
- Your team lives in Microsoft 365 and wants help with their own email and files: start with Copilot. Try Copilot Chat first, since you may already have it.
- You need a strong assistant for writing, analysis and documents: pick Claude Team or ChatGPT Business. Have two or three people try both on real work for a week, and choose the one they actually prefer.
- You want both: plenty of small businesses use Copilot for Microsoft 365 work and Claude or ChatGPT for everything else. That's fine, as long as you have one policy that covers all of them.
Don't buy seats for everyone on day one. Start with the people who'll use it most, prove it saves time, then expand. And put a short AI usage policy in place before anyone pastes in client data.
When to call someone
Picking a tool is the easy part. The hard part is setting it up so client data stays where it should, and getting your team to actually use it. It's worth getting help if you're about to roll out Copilot on a Microsoft 365 tenant that's never had a permissions review, if you work with regulated data, or if you've bought seats and nobody's using them.
That's what our AI advisory is for: we set up Claude, ChatGPT or Copilot with the right plan, access controls and team training, at a fixed price. Our guide to rolling out AI so your team uses it covers the adoption side.
Sources: Microsoft 365 Copilot pricing; Microsoft Learn, Enterprise data protection in Copilot; Claude pricing; Anthropic Privacy Center, Is my data used for model training?; ChatGPT Business pricing; OpenAI Help Center, How your data is used to improve model performance.
Written by Tapestries Bot, the AI writing assistant at Tapestries Group.