ChatGPT vs Claude vs Microsoft Copilot: Which Should Your Business Use?

The most common question I’m asked, by some distance: “Which one should we use?” Here’s the honest, independent answer, I don’t resell any of them, so there’s no commission influencing this.

The short version

• Already living in Microsoft 365 (Outlook, Word, Teams, SharePoint)? Copilot deserves first look, because it works where your data already lives.
• Doing lots of writing, summarising or long-document work? Claude is exceptional with long documents and produces notably natural writing.
• Want the biggest ecosystem and most general-purpose tool? ChatGPT has the widest feature set and the most integrations, custom GPTs and community knowledge.

And the secret nobody selling you a licence mentions: for most small business tasks, all three are excellent. The gap between “using any of them well” and “using none” is enormous; the gap between them is small. Don’t let tool choice become another reason to delay.

What actually differs

Where they meet your data. Copilot’s superpower is context: it can read the email thread, the document, the meeting transcript, because it’s inside your Microsoft tenancy. ChatGPT and Claude are destinations you bring work to (though both now connect to files and apps too, and Claude’s Projects feature is genuinely useful for keeping business context around).

Writing quality. Subjective, but a consistent pattern in my client work: Claude tends to produce the most natural British business writing with the least “AI voice”; ChatGPT is a strong all-rounder; Copilot’s drafting is improving fast but can be the most generic of the three.

Long documents. Claude handles very long documents (contracts, tender packs, reports) especially well, which is why it features heavily in my work with solicitors and professional services firms.

Price. Broadly similar for business tiers, roughly £15–25 per user per month depending on tool and plan. Copilot needs a qualifying Microsoft 365 subscription underneath it. All three offer meaningful free tiers for testing (see how to get started for free).

Data protection. All three offer business tiers where your data isn’t used to train models, but only the business tiers, configured correctly. This is the non-negotiable, and it’s the same conversation whichever you pick: read Is AI Secure? before rolling anything out to a team.

How to actually decide

1. Audit what you already pay for. If Microsoft 365 Business is in place, trial Copilot with two or three licences before buying anything new.
2. Match the tool to your heaviest word-work. Long documents and careful writing → Claude. Broad general use and integrations → ChatGPT. Email/meetings/Office files → Copilot.
3. Trial one for a month with two people. Real work, real measurement: hours saved, quality after editing, whether people actually reach for it.
4. Don’t buy for everyone on day one. Roll out to the people whose jobs are word-heavy first; expand when the value is proven.

The part that matters more than the choice

Whichever tool you choose, the outcomes depend far more on three things: setup (business accounts, privacy settings, shared prompts), skills (fifteen minutes of prompting technique doubles output quality), and workflow fit (using it on the right tasks). That’s the gap the AI Essentials Workshop and AI Setup & Implementation close, and if you want a recommendation specific to your business rather than general principles, that’s precisely what the free AI Opportunity Report gives you.