Microsoft 365 Copilot or ChatGPT? Choosing the Right AI Assistant for Your Business

Short answer: if your company's work lives in Microsoft 365 (Outlook, Teams, SharePoint, OneDrive) and access permissions matter, Microsoft 365 Copilot is usually the more natural fit, and the Copilot Chat included with work accounts is a good starting point at no additional licence cost. ChatGPT, on its Business and Enterprise plans, is a strong tool for general-purpose writing, analysis and coding. Many companies end up using both. The real risk is not picking "the wrong one": it is letting employees use personal accounts with company data.

Four products, not two

When someone asks “Copilot or ChatGPT?”, they are usually comparing different things. For a serious decision it helps to separate four offerings:

• Microsoft 365 Copilot — the paid add-on licence that brings AI into Word, Excel, PowerPoint, Outlook and Teams and grounds answers in your organisation’s data through Microsoft Graph. For SMEs, Microsoft offers Microsoft 365 Copilot Business, for organisations of up to 300 users, with the same capabilities.
• Microsoft 365 Copilot Chat — the AI chat included at no additional cost for users with a Microsoft Entra account and an eligible Microsoft 365 subscription. It answers mainly from the web; it only works with company content when the user uploads a file, is working in an open document or email, or through pay-as-you-go agents.
• ChatGPT Business — OpenAI’s team plan, called ChatGPT Team until 29 August 2025. The change was name-only.
• ChatGPT Enterprise — the plan for larger organisations, bought directly from OpenAI, with more admin controls and data residency options.

Left out of this comparison is free or Plus ChatGPT on a personal account: it is not a business product, and that is exactly where the shadow AI problem starts.

Comparison table

Information checked against Microsoft’s and OpenAI’s official pages as of October 2026. These products change quickly; always confirm current terms before deciding.

	Microsoft 365 Copilot (paid add-on)	Microsoft 365 Copilot Chat (included)	ChatGPT Business	ChatGPT Enterprise
Access to company data	Automatic via Microsoft Graph: email, Teams, SharePoint, OneDrive, respecting each user’s existing permissions	Web by default; company content only via upload, open document/email or paid agents	Uploads and connectors (e.g. SharePoint, Outlook, Teams) enabled by the admin; connectors respect the user’s permissions	Same as Business, with additional admin-managed sync options
Training on your data	No: prompts, responses and Graph data do not train the foundation models (Enterprise Data Protection)	No: also covered by Enterprise Data Protection	Not by default, under OpenAI’s business terms	Not by default, under OpenAI’s business terms
Admin and governance controls	Microsoft 365 admin center, Microsoft Purview (audit, retention, eDiscovery), sensitivity labels	The same Microsoft 365 tenant controls	Workspace console, SSO, app and connector management	More advanced controls (SSO/SCIM, roles, retention)
EU data residency	Covered by Microsoft’s EU Data Boundary	Covered by Microsoft’s EU Data Boundary	Rolling out gradually, not yet available to all customers; data at rest only, no in-region inference	Available to eligible customers, including data at rest in Europe and a European inference option
Integration into Word, Excel, Outlook, Teams	Native, inside the apps	Chat pane in the apps, without the full add-on features	Via apps/connectors and a ChatGPT app in Teams; outside the Office apps	Same as Business
Agents	Copilot Studio and Microsoft 365 agents, with access to company data	Agents available, with pay-as-you-go billing for those using shared tenant data	Custom GPTs and agent features	Custom GPTs and agents, with organisation sharing controls
Pricing model	Per-user monthly licence with annual commitment, on top of an eligible Microsoft 365 licence	No additional cost; agents metered by consumption (requires an Azure subscription)	Per-user subscription (monthly or annual), with distinct seat types	Purchased through OpenAI’s sales team

On pricing: Microsoft’s official pricing page lists Microsoft 365 Copilot for enterprises at USD 30 per user/month paid yearly as of October 2026, and there are Microsoft 365 Business Standard and Business Premium bundles with Copilot included. Prices vary by country and billing term, so confirm local pricing on Microsoft’s site or with your partner. For a fuller cost-benefit view, see our Microsoft 365 Copilot ROI guide.

The difference that actually matters: context and permissions

On writing quality or reasoning ability, both ecosystems use frontier models and the day-to-day gap keeps shrinking. What separates the tools is where the context lives and who controls access.

Microsoft 365 Copilot does not need anyone to copy and paste information: when a user asks “summarise yesterday’s meeting decisions and the emails from client X”, the answer comes from Teams and Outlook, limited to what that user can already see. Security rests on the permissions the company already has in Microsoft 365.

ChatGPT can now also connect to SharePoint, Outlook and Teams through connectors, and OpenAI states these respect existing permissions. The difference is that it is one more integration to configure and govern, with permissions approved in Microsoft Entra and a second vendor processing company data. That is not necessarily worse; it is one more piece in the architecture.

The critical point is the same in both cases: if SharePoint permissions are wrong, any AI assistant will expose the problem. A folder accidentally shared with “everyone in the organisation” is now one question away.

When to choose each

Microsoft 365 Copilot makes sense when

• The company already works in Microsoft 365 and its documents, emails and meetings are there.
• The value lies in tasks on internal data: summarising Teams meetings, drafting replies in Outlook, analysing spreadsheets in Excel, finding information in SharePoint.
• You want governance centralised where you already manage identity, compliance and retention (Entra, Purview).
• You want to build agents tied to internal processes with Copilot Studio. We cover that path in our article on AI agents in Microsoft 365.

Start with Copilot Chat when

• You do not yet know which teams will benefit most from AI and want to give the whole organisation a safe option at no additional licence cost.
• The immediate goal is to replace personal tools with a chat covered by Enterprise Data Protection, while measuring adoption before buying paid licences.

ChatGPT Business or Enterprise makes sense when

• The main use is general-purpose: writing, brainstorming, analysing uploaded data, coding support.
• The company is not centred on Microsoft 365, or has teams working mostly outside the Office apps.
• Specific roles (development, marketing, research) benefit from OpenAI’s own features.
• For Enterprise, if European data residency is a requirement, confirm eligibility directly with OpenAI.

Using both is common, and legitimate

Many organisations give Copilot Chat or Microsoft 365 Copilot to everyone and a limited number of ChatGPT seats to specific teams. This works well as long as both tools are under a business contract, with clear rules on which data can go into each.

The scenario to avoid is different: employees using personal ChatGPT accounts (or any other AI) with client data, proposals or financial information. That is shadow AI: the company does not know what data left, does not control retention and loses the guarantees of the business terms. Banning rarely works; offering an approved alternative and explaining why works far better.

Governance before rollout

Whatever you choose, four tasks should be done before opening AI to the whole company:

1. Review permissions and oversharing in SharePoint and OneDrive. Sites open to “everyone”, anonymous sharing links and inherited groups are the number one risk. AI respects permissions; the problem is when the permissions are wrong.
2. Apply sensitivity labels. With Microsoft Purview, documents classified as confidential can carry protection that travels with the file, including into Copilot responses.
3. Publish an AI acceptable-use policy. Short and practical: which tools are approved, which data must never go into any AI, how to check answers, who to report problems to.
4. Meet the EU AI Act AI literacy duty. Article 4 requires organisations that use AI systems to ensure a sufficient level of AI literacy among their staff. We detail what this means for an SME in our article on the EU AI Act for your company.

If adoption has already started without these foundations, our article on Copilot without governance shows how to bring order without stifling innovation.

Frequently asked questions

Is the free Copilot Chat the same as Microsoft 365 Copilot?

No. Copilot Chat is included at no additional cost for eligible work accounts and has Enterprise Data Protection, but it answers mainly from the web and only uses company content the user uploads or has open. The paid Microsoft 365 Copilot automatically reaches email, Teams, SharePoint and OneDrive through Microsoft Graph and works inside the Office apps.

Is it safe to put company data into ChatGPT?

On the business plans (Business and Enterprise), OpenAI states it does not use workspace data to train models by default, and offers a data processing agreement. On a free or Plus personal account, the company has neither those contractual guarantees nor any control. Rule of thumb: company data only goes into tools the company has contracted.

Does Microsoft 365 Copilot use our data to train its AI?

No. According to Microsoft’s documentation, prompts, responses and data accessed through Microsoft Graph are not used to train the foundation models. The same applies to Copilot Chat with a work account.

Does ChatGPT store data in Europe?

It depends on the plan. On ChatGPT Enterprise, eligible customers can store content at rest in Europe and run inference in the region. On ChatGPT Business, data residency was, as of October 2026, rolling out gradually and covers storage only, not processing.

Can we use Copilot and ChatGPT at the same time?

Yes, and many companies do. What matters is that both are under a business contract, that a policy states which data can go into each tool, and that employees know which one to use in each situation.

Conclusion: decide by context, govern before you scale

The right question is not “which AI is best?” but “where does our work live, and how do we control who sees what?”. For most SMEs already working in Microsoft 365, the sensible path is to start with Copilot Chat, fix permissions and policy, and then license Microsoft 365 Copilot for the teams where the gain is clear. Business ChatGPT can complement it where it makes sense.

If you want to move forward safely, explore our Microsoft 365 Copilot and AI adoption service, read the Copilot ROI guide and our article on Copilot governance, or book a demo and we will review your starting point.