GILD verdict
Start with Copilot Chat for everyone and paid Copilot for Outlook, Teams and SharePoint roles, then add ChatGPT seats by role.
- The workflow
- Licensing an assistant for knowledge workers whose mail, files and meetings already live in Microsoft 365
- The decisive evidence
- ReportedThe UK Ministry of Justice runs targeted rollouts of Copilot for Microsoft 365 and ChatGPT Enterprise side by side, and Penn State sells both licences to staff.111314
- ReportedAt La Trobe University ChatGPT became the dominant tool although Copilot started first, and the university plans 40,000 ChatGPT Edu licences by 2027.12
- DocumentedAt 200 seats, Copilot Business costs US$4,200 a month over Microsoft 365 and ChatGPT Business US$4,000 as its own workspace, by GILD's calculation from published rates.29
- GILD analysisNo organization GILD found has published a head-to-head of the two on the same tasks, so the split by role rests on where each one reads the work.
- The tradeoff
- ChatGPT fits staff who work across other tools. Two assistants mean two data agreements, two retention settings and two training plans, and Copilot's price sits on top of a Microsoft 365 plan the ChatGPT price does not need.
- What would change the call
- If a pilot shows your Copilot users rarely leave the Microsoft 365 apps, skip the second seat; if they keep opening ChatGPT anyway, as at La Trobe, license ChatGPT for those roles.
Public organizations that run both license them by role: the UK Ministry of Justice rolls out Copilot for Microsoft 365 and ChatGPT Enterprise side by side, and Penn State sells both to staff. The paid Copilot license reads each person's mail, files, and meetings in place through Microsoft Graph; ChatGPT reaches them through connectors each user signs in to. At La Trobe University, ChatGPT became the dominant tool although Copilot arrived first.
What teams report
Run both 1
UK Ministry of Justice
The Ministry of Justice reported on September 24, 2026 that it runs targeted, ongoing rollouts of Copilot for Microsoft 365 and ChatGPT Enterprise side by side.
“…targeted, ongoing rollouts of Copilot for Microsoft 365 and ChatGPT Enterprise…”
Ministry of Justice, Department, AI Action Plan for Justice, UK Ministry of JusticeGOV.UK (Ministry of Justice), , paper
Adopted 1
La Trobe University
La Trobe plans 40,000 ChatGPT Edu licences for staff and students by the end of financial year 2027, with 5,000 in the current year, and iTnews reported on December 17, 2025 that ChatGPT had become its dominant AI tool although Copilot started first.
“OpenAI’s ChatGPT has emerged as La Trobe University’s dominant generative AI tool despite Microsoft’s Copilot having had a headstart in the research-focused education institution.”
Andrew Colley, Journalist, iTnewsiTnews, , reportSecond-hand, as iTnews reported it
Choosing between Microsoft Copilot and ChatGPT
Choose Microsoft Copilot if
- Your company runs on Microsoft 365, and the work people want help with sits in Outlook, Teams, Word, and SharePoint.
- You want a baseline for everyone at no added cost through Copilot Chat, with paid licenses only for the roles that need answers grounded in their own work data.
- Your compliance team already governs Microsoft 365 with Purview, sensitivity labels, and retention, and wants those to apply to the assistant.
Choose ChatGPT if
- Your people want a standalone assistant for writing, analysis, and research that works the same way across every tool they use.
- Your knowledge is spread across Microsoft 365, Google Drive, Slack, and GitHub, so one workspace with connectors fits better than a suite assistant.
- You want ChatGPT Work, custom team plugins, and Codex in the same seat, from US$20 per user per month billed annually.
- Staff already reach for ChatGPT on their own, as at La Trobe University, where ChatGPT Edu overtook a Copilot that started first.
Side by side
| Dimension | Microsoft Copilot | ChatGPT |
|---|---|---|
| Included at no extra cost | Copilot Chat for Entra users on eligible Microsoft 365 plans, web grounded, with limited grounding in Outlook | ChatGPT Free for individuals; a business workspace is a separate purchase |
| Paid business priceList prices in US dollars. Copilot's prices are add-ons to a Microsoft 365 plan; ChatGPT's are a standalone workspace. | Microsoft 365 Copilot US$30 per user per month paid yearly, on top of a qualifying plan. Copilot Business US$21 paid yearly, or US$25.20 monthly, with a US$18 first-year promotion through December 31, 2026. Included in E7 at US$99 | ChatGPT Business US$20 per user per month billed annually or US$25 monthly, two users minimum; Enterprise by quote |
| What it reads | With a license, Microsoft Graph and Work IQ across the email, files, meetings, calendars, and chats a user can open, plus Copilot connectors | Files people upload and connected apps such as Microsoft 365, Google Drive, Slack, and GitHub, each user authenticating to every app |
| Inside the Office apps | Copilot in Word, Excel, PowerPoint, Outlook, OneNote, and Teams, including Teams meeting recaps | Extensions for Excel, Word, PowerPoint, and Google Sheets |
| Usage beyond the seat | Copilot Cowork and agents for Chat users are metered through Copilot Credits or an Azure subscription | Business and Enterprise can buy credits for more access beyond included usage |
| Model training | Prompts, responses, and Microsoft Graph data are not used to train foundation LLMs | Business data is not used for training by default |
| Retention | Interactions stored with other Microsoft 365 content and governed by Purview retention policies, searchable for eDiscovery | Workspace admins control retention; deleted or unsaved conversations are removed within 30 days unless the law requires longer |
| Models | OpenAI models, and Anthropic models as a subprocessor, on by default outside the EU, EFTA, and UK | OpenAI's GPT-6 family, with flexible access on Business and Enterprise |
| 200 seats a month200 seats, list prices, no metered agents, Cowork or credits, taxes or negotiated discounts. | US$4,200 on Copilot Business at US$21 a seat paid yearly, over an existing qualifying Microsoft 365 plan. GILD's calculation from published rates, read Oct 28, 20262 | US$4,000 on ChatGPT Business at US$20 a seat billed annually. GILD's calculation from published rates, read Oct 28, 20269 |
| Who runs both | The UK Ministry of Justice and Penn State license Copilot beside ChatGPT, for work inside the Microsoft 365 apps1113 | The same two license ChatGPT Enterprise or ChatGPT Edu by role; La Trobe University plans 40,000 ChatGPT Edu licences111214 |
What practitioners report, side by side
Each product's figures come from its own practitioners, for the group you pick.
Overall signal
Leaders and teams rate ChatGPT +14, 17 points above Microsoft Copilot at −3. Most of the gap is in praise, with 17 of ChatGPT's 38 sources positive against 12 of Microsoft Copilot's 40. ChatGPT has 10 negative and Microsoft Copilot 13.
The score counts the authors from leaders and teams that take a side, one vote each with their latest view, and is how far positive votes lead negative ones, per 100 votes, so Microsoft Copilot's −3 rests on votes split 12 positive, 13 mixed and 13 negative and ChatGPT's +14 on 15, 11 and 10.
A lead of a fifth of the votes reads positive and a lead of half strong positive, with the same lines below zero. The dots show each source, positive, mixed, negative. Run a pilot on your team's recurring tasks to measure how often answers are used without rework.
Footprint on the AI Knowledge Work stack
They differ on one of 7 layers. On Enterprise search, Microsoft Copilot is core and ChatGPT supports it. Coverage is each product's placement on this stack, as its product page shows it. Core is a job the product owns; Supports and Touches are jobs it helps with. Coverage says nothing about how well a product does them.
| Layer | Microsoft Copilot | ChatGPT |
|---|---|---|
| Find | ||
| Enterprise search | Core | Supports |
The 6 layers where they match
| Layer | Microsoft Copilot | ChatGPT |
|---|---|---|
| Assist | ||
| AI assistant | Core | Core |
| Find | ||
| Web research | Supports | Supports |
| Create | ||
| Documents | Supports | Supports |
| Meeting notes | Supports | Supports |
| Analyze | ||
| Data analysis | Supports | Supports |
| Automate | ||
| Automation | Supports | Supports |
What practitioners praise
Among leaders and teams, Microsoft Copilot alone has three praise themes that reach 5 sources from 3 authors. Meeting Recaps and Enterprise Data Terms lead, at 5 of 5 and 5 of 7. Custom GPTs, Projects & Memory reaches 5 sources from 3 authors only for ChatGPT, at 3 of 5. Microsoft Copilot needs a pilot on the same tasks before you choose on it.
| Praised for | Microsoft Copilot | ChatGPT |
|---|---|---|
| Meeting Recaps | 5 of 5 | Not a theme in its sources |
| Enterprise Data Terms | 5 of 7 | Not a theme in its sources |
| Agents & Cowork | 4 of 10 | Not a theme in its sources |
| Custom GPTs, Projects & Memory | Not a theme in its sources | 3 of 5 |
Each count is the sources that praise a theme, or raise it as a concern, out of those that discuss it. A row pairs the two products when both carry a theme under the same or an equivalent name.
A count ending in "so far" has under 5 sources from 3 authors among leaders and teams. "Not a theme in its sources" means GILD found no theme of that name in that product's sources.
What practitioners raise as concerns
Among leaders and teams, Microsoft Copilot alone has four concern themes that reach 5 sources from 3 authors. Admin Controls and Oversharing lead, at 6 of 6 and 5 of 5. ChatGPT alone has three concern themes that reach 5 sources from 3 authors. Workspace Administration and Usage Limits & Cost lead, at 7 of 10 and 6 of 9.
| Raised as a concern | Microsoft Copilot | ChatGPT |
|---|---|---|
| Admin Controls | 6 of 6 | Not a theme in its sources |
| Oversharing | 5 of 5 | Not a theme in its sources |
| License Cost & Confusion | 5 of 6 | Not a theme in its sources |
| Low Adoption | 4 of 5 | Not a theme in its sources |
| Workspace Administration | Not a theme in its sources | 7 of 10 |
| Usage Limits & Cost | Not a theme in its sources | 6 of 9 |
| Data Privacy & Retention | Not a theme in its sources | 3 of 8 |
14 sources
- Microsoft: Microsoft Copilot for enterprise, plans and pricing
- Microsoft: Microsoft Copilot for business, plans and pricing
- Microsoft: Microsoft 365 E7
- Microsoft Learn: Overview of Microsoft Copilot Chat
- Microsoft Learn: Data, privacy, and security for Microsoft Copilot
- Microsoft Learn: Anthropic models in Microsoft Online Services
- Microsoft Learn: Microsoft Copilot pay-as-you-go service overview
- Microsoft Learn: Copilot Cowork FAQ
- ChatGPT pricing
- OpenAI: Enterprise privacy at OpenAI
- GOV.UK: AI Action Plan for Justice, one year on (Sep 24, 2026)
- iTnews: OpenAI gets edge over Microsoft Copilot at La Trobe (Dec 17, 2025)
- AI at Penn State: M365 Copilot service page (undated, read Oct 28, 2026)
- AI at Penn State: ChatGPT Edu service page (undated, read Oct 28, 2026)