The short answer
Choose by where work already lives. Microsoft 365 Copilot works in Outlook, Teams, Word and Excel with your existing permissions; Gemini does the same in Gmail, Docs and Drive; ChatGPT's business plans are a strong standalone assistant across tools. All three say business data is not used for training by default, so compare reach, admin controls and integration. Need strict control over specific systems? A custom assistant often fits better.
Where each one fits
We are not a partner or reseller of any of these vendors: we recommend on fit.
Microsoft 365 Copilot
Now Microsoft Copilot. Works in Microsoft 365 apps on content each user can already access.
Copilot Chat
Web-grounded, with enterprise data protection; uses your content only in set ways, such as added files.
Gemini in Google Workspace
Gmail, Docs, Drive, Meet, the Gemini app and Gemini Notebook (formerly NotebookLM), on qualifying editions.
ChatGPT Business and Enterprise
Dedicated workspace; admin-enabled apps connect internal and third-party sources. Build your own via OpenAI's API.
Mixed platforms, or neither central? Consider a standalone or custom assistant.
How each handles your organisation's data
Per each vendor's business privacy page, October 2026. Terms change: confirm current versions.
| Microsoft 365 Copilot | ChatGPT business plans | Gemini in Google Workspace | |
|---|---|---|---|
| Training on your data | Prompts, responses and Graph data not used for foundation models | Not by default, unless you opt in | Not without your prior permission or instruction |
| What it can reach | Content the user can at least view | Sources connected by admin-enabled apps | Content the user may access |
| Existing permissions | Respected, per Microsoft | Respected for connected apps; each user authenticates | Respected, per Google |
| Human review | Opted out of Azure OpenAI abuse monitoring (which includes human review) | Limited, varies by plan | None outside your domain without permission |
Two cautions. Business terms do not cover personal accounts (OpenAI says it trains on data from its services for individuals): insist on work accounts. And ask where prompts are processed: Microsoft says Copilot queries from customers outside the EU may be processed in the US, the EU or elsewhere; Workspace data region settings do not apply to Gemini Notebook.
Example admin controls
- Microsoft 365 Copilot: choose allowed agents; retention and search through Microsoft Purview.
- ChatGPT business plans: SAML single sign-on; control over access, features and apps; retention settings.
- Gemini in Google Workspace: Gemini app on or off; conversation retention; data loss prevention on generated content in supported editions.
Questions to ask every vendor
- Can we enforce SSO and MFA, and add and remove users automatically?
- Admin-set retention; search or export prompts and responses for investigations?
- Do our data loss prevention rules cover prompts and outputs?
- Which connectors, apps and agents can users add? Can we approve each?
- Which models and subprocessors are used, and can we choose?
- Is web search used for answers, and can we turn it off?
- Where are prompts processed and stored for our plan and region?
Example: model choice
Microsoft, for instance, lets administrators decide whether to use the Anthropic and OpenAI models it offers in Copilot.
Integration with your other systems
None knows your ERP, CRM or line-of-business apps out of the box; connecting them (connector, app or agent) is most of the real work. Options vary by vendor and plan and change often: test the exact connection, with real permissions, in a pilot. Treat links to Prometheus or ERPNext or other systems as system integration work, not an afterthought.
When a custom assistant is better
A general assistant is the right default for everyday drafting, summarising and searching. A custom AI assistant is often better for:
- Approved sources only, with citations
- Data in an ERP, CRM, document system or file shares
- Complex permissions: client matters, health records, project teams
- Control of model, processing location and logging
- Inside your own portal or application
- A few processes, where per-user licences for all do not fit
See how AI assistants answer from your documents. Many organisations run both: a suite assistant for daily work, a custom one for a specific process. Confidential data barred from outside AI providers, or required to stay in Nigeria? Run an open-weight model on servers you control (private AI and self-hosted models).
Rather talk it through? If you are weighing Copilot, ChatGPT and Gemini, or wondering whether you need something custom, we can compare them against your systems, data and controls. Talk to a Promatics specialist
How to decide
- Where work livesMicrosoft 365, Google Workspace or a mix.
- What it must reachEmail and documents, or also ERP, CRM and other systems.
- Non-negotiable controlsRetention, data loss prevention, data location, connector approval.
- Pilot real tasksSmall group, real work, agreed measures, ideally two options side by side.
- Confirm with vendorCurrent terms and pricing before signing, not comparison articles (this one included).
When to bring in help
Do it yourself on one platform with tidy permissions and everyday needs: pick the matching assistant, pilot briefly under a clear policy.
Bring in help for mixed platforms, health, financial or client confidential data, business-system access, or when leadership needs evidence first. Our Microsoft 365 Copilot service covers readiness, oversharing clean-up, pilot and adoption; for Google Workspace or no single platform, AI strategy and readiness compares options on your tasks. Tied to no vendor, we follow your systems, data and budget.
Sources and further reading
Product capabilities and guidance change. These are the primary sources this article relies on, checked on the review date above.
- Data, privacy and security for Microsoft Copilot, Microsoft Learn
- Microsoft Copilot Chat privacy and protections, Microsoft Learn
- Enterprise privacy at OpenAI, OpenAI
- Generative AI in Google Workspace Privacy Hub, Google Workspace
- Nigeria Data Protection Act 2023, Nigeria Data Protection Commission
This article is general information, not legal, accounting or security advice for your specific situation. Examples are hypothetical unless stated otherwise.