Copilot vs ChatGPT for a Small Business: UK Prices

Verdict

The two cost about the same, so the choice is about where your team already works. Microsoft 365 Copilot is built into Microsoft's apps, including Outlook, Word and Excel. ChatGPT is a separate tool that works alongside Microsoft or Google tools. Neither wins for everyone, so here is a pick for each situation.

• You already pay for Microsoft 365. Start with Copilot Chat, which Microsoft includes at no additional cost with eligible plans and which also works in Outlook. Add the paid Copilot for the few people who need it in Word, Excel and PowerPoint, and broader search across your files.
• You use Google Workspace. Look at the Gemini assistant already in your plan before paying for anything. Choose ChatGPT Business if you want a separate tool.
• You want one tool for writing, whatever email you use. ChatGPT Business needs no existing plan and works alongside Microsoft or Google tools, but it needs two seats at least.

We compared the plans that matter to a business of 1 to 30 people. We have not tested which one writes or analyses better, so we make no claim on that. Everything below comes from each vendor's own pages, read on 2 November 2026.

Prices

We use one basis: yearly billing, per person a month, in pounds. Microsoft's pages say their prices exclude VAT. OpenAI's pricing page does not say, so we cannot tell you whether its £15 includes VAT.

OpenAI's pricing page shows the ChatGPT Business Standard seat at £15 a month on yearly billing and £18 on monthly billing, for teams of 2 to 200. Its help centre says a workspace needs at least two paid seats, so a one-person business cannot buy it.

Microsoft's Copilot page shows the Copilot Business add-on at £16.10 a user on yearly billing and £19.32 on monthly. The add-on is for people who already have an eligible Microsoft 365 Business plan, which starts at £5.40 a user a month for Business Basic on yearly billing. Business Standard with Copilot, which bundles the Office apps and Copilot, is £18.10 yearly with Teams or £15.60 without it, on the page's "Plans without Teams" tab, and £21.72 monthly with Teams.

Three details change the sum:

• A temporary discount. Microsoft's page shows the add-on at £13.80 for the first year, but its own footnote says the offer runs from 1 July to 31 December 2026, needs an annual commitment, is for existing Microsoft 365 customers with an eligible Business plan, and is not available on trial subscriptions. We priced the table at the normal £16.10.
• Extras billed by use. Microsoft says everyday chat and Copilot in the apps are included, while advanced features such as Copilot Cowork and Autopilot are billed by usage. Administrators can set spending limits.
• Seat sizes. OpenAI also sells a Premium seat at £75 a month on yearly billing, with five times the usage. Most small teams will not need it.

For 10 people on yearly billing that is £150 a month for ChatGPT Business (10 at £15) and £161 for the Copilot add-on (10 at £16.10), before any VAT. The add-on comes on top of a Microsoft 365 Business plan you already pay for, so the like-for-like cost depends on the plan you have.

Office Apps

This is where the two differ most. Copilot is part of Microsoft's apps. ChatGPT reaches them through add-ins and connections.

Copilot. Microsoft lists Copilot in Word, Excel, PowerPoint, Teams and Outlook on its business page, including catching up on email and drafting responses in Outlook. Its Copilot Chat overview says Copilot Chat works in Outlook for eligible users without the paid add-on, and can answer questions across your emails, calendar and meetings there. Full Copilot in Word, Excel and PowerPoint, with priority access, needs the paid licence. Some unlicensed users get standard access, depending on set-up. Outlook has its own requirements for this, and we did not check every account type.

ChatGPT. OpenAI's Word add-in opens ChatGPT in a sidebar inside Word, and the same add-in covers Excel and PowerPoint. It is on every ChatGPT plan, Free included, and your administrator must also allow it in Microsoft 365. The Excel add-in works the same way, and also works in Google Sheets.

For email, OpenAI's Outlook app lets ChatGPT search your messages and draft replies, but you work in ChatGPT, not in an Outlook panel. We found no OpenAI page that describes a ChatGPT panel inside Outlook, so we do not claim one. Some of its permissions need a Microsoft administrator to approve them.

Data and Training

Training means a vendor uses your text to improve its models. Microsoft says business prompts and responses are not used to train its models. OpenAI says it does not train on business data by default, and only if your organisation explicitly opts in.

• Microsoft. Its privacy page says prompts, responses and data accessed through Microsoft Graph are not used to train its models. It also covers Copilot Chat under enterprise data protection.
• OpenAI Business. OpenAI's business privacy page says it does not train on your business data by default. Its data-use page adds that thumbs up or down feedback does not allow training on a Business conversation.
• ChatGPT Free. The same page says that on Free, Plus and Pro, OpenAI may use your content to train its models unless you turn Improve the model for everyone off in Settings under Data controls. If someone presses thumbs up or down, that whole conversation may still be used.

The risk for a small firm is rarely the paid plan. It is a member of staff pasting a client's details into a personal free account. If that happens, those chats sit under the individual rules above.

Where the data is kept is less clear for a UK firm. Microsoft says worldwide traffic can be processed in the EU and other regions, and keeps its EU Data Boundary promise for EU customers. OpenAI says storage regions for Business are rolling out gradually, cover storage only, and a copy of each prompt is kept in the United States for a limited time. OpenAI's pricing page lists data residency in ten regions, the UK among them, under its Enterprise plan, and its Business page names no regions. Microsoft's page makes no UK-only statement. If you need one, ask the vendor in writing.

Admin Controls

On ChatGPT Business, OpenAI's pricing page lists single sign-on, multi-factor authentication, centralised billing, usage analytics and spend controls. Your administrator can switch the Word add-in on or off.

Microsoft's controls come from Microsoft 365 itself. Its Copilot page says Copilot follows your existing security settings. The enterprise data protection page adds that it inherits your sensitivity labels and retention policies, and supports audit of what people ask. The add-on also includes usage analytics.

One practical point: Copilot can read whatever a person can already open. Before switching it on, check who can open what in your shared folders.

Included Tiers

Copilot Chat is not something you can buy alone. Microsoft says it is included at no additional cost with eligible Microsoft 365 plans, so you need a paid plan. Microsoft 365 Business Basic, at £5.40 a user a month on yearly billing before VAT, lists an AI chat in its highlights. Its overview warns that standard access depends on service capacity.

ChatGPT Free gives unlimited text chats (subject to abuse guardrails), with limits on uploads, images, voice and research. It is worth trying. The training rules above apply, so keep client details out of it.

Situations

You already use Microsoft 365. Copilot Chat is included, so try it first. Add Copilot Business only for the people who would use Copilot in Word, Excel and PowerPoint daily. A team of 10 where 3 people need it adds 3 at £16.10 on yearly billing, not 10, on top of the plan you already pay for.

You use Google Workspace. Google's pricing page lists a Gemini assistant in Gmail on Business Starter, at £5.90 a user a month on yearly billing, with Gemini in Docs, Sheets and Slides from Business Standard. It says your company data is not used to train models. Copilot's apps are Microsoft's, so it only makes sense if you use them. ChatGPT Business connects to Google Workspace too, and needs no existing plan.

You want one tool for writing. ChatGPT Business works alongside Microsoft or Google tools and needs no existing plan, but it needs two seats at least. The data rules above are the reason to buy the business plan instead of letting staff use free accounts.

You are a sole trader. ChatGPT Business needs two paid seats. Microsoft's business plans start at one user. Try ChatGPT Free, or Copilot Chat if you have a Microsoft 365 plan, and read the training settings before pasting anything about a client.

Tunewell

The choice of tool is one small part of the work. When we do a Check-Up, we look at how your business runs, then tell you which tools to use and which to skip. We pick what fits the tools you already have, say when a cheaper one is enough, and take no commission from any of them. A Check-Up is £495 for up to 10 staff and includes one Quick Win, chosen from More Reviews, Invoices Chased or Weekly Numbers, set up and working.

You do not need us for this choice. ChatGPT Free, Copilot Chat if you have Microsoft 365, and Microsoft's free trial are enough to decide. If you would rather have a second opinion, see the Menu of jobs we set up, or book a free 30 minute Intro Call.