How to Use ChatGPT with Microsoft Office: The 2026 Guide for Companies (Word, Excel, Outlook, Teams, PowerPoint, SharePoint)

Most companies still use ChatGPT as a separate browser tab. Employees draft in Word, build models in Excel, prep decks in PowerPoint — then context-switch to ChatGPT, paste content in, paste answers back out. It works, but it leaks time, leaks data, and leaves 80% of the value of generative AI on the table. In 2026, every Microsoft 365 customer has two cleaner paths: install ChatGPT directly inside Office through add-ins, or connect ChatGPT to OneDrive, SharePoint, Outlook and Teams through the GPT store. This guide walks through both — plus when to pay for ChatGPT, when to pay for Microsoft 365 Copilot, and when to do both.

ChatGPT, Microsoft 365 Copilot and Copilot Chat: What's Actually Different?

Before wiring anything up, get the landscape straight — because the names are deliberately confusing.

• ChatGPT (Free, Plus, Pro, Team, Business, Enterprise) is OpenAI's product. It lives at chatgpt.com and in the ChatGPT desktop and mobile apps. It connects to Microsoft 365 through add-ins inside Office and through connectors in the ChatGPT "apps" / GPT store.
• Microsoft 365 Copilot is Microsoft's product. It lives inside Word, Excel, PowerPoint, Outlook and Teams as a sidebar and a set of in-app buttons. It is grounded by default in your Microsoft 365 data via Microsoft Graph.
• Microsoft 365 Copilot Chat is the free, web-grounded chat experience available to anyone with a Microsoft Entra ID — think of it as Microsoft's answer to free ChatGPT, with enterprise data protection on top. Paid Copilot adds in-app actions and tenant-grounded answers.
• Copilot is multi-model. Microsoft has confirmed Copilot now runs on a mix of OpenAI's GPT family and Anthropic's Claude models, picking the right model per task. We covered this in detail in our Microsoft Copilot Cowork guide.

In other words: if you pay for Microsoft 365 Copilot, you are already paying for ChatGPT-class models — just routed through Microsoft. The question for most companies is whether you also want OpenAI's ChatGPT product surface for your team, and how to make the two play nicely with Office.

Indicative 2026 Pricing: ChatGPT vs Microsoft 365 Copilot

Pricing changes constantly — always check vendor pages before you sign — but as of mid-2026, this is the order of magnitude most companies plan around:

Plan	Indicative price (per user / month)	What it gets you
ChatGPT Plus	~$20	Individual plan, GPT-5 / o-series models, connectors to OneDrive, SharePoint, Outlook, Teams.
ChatGPT Business / Team	~$25-30	Team workspace, admin console, no training on your data, shared GPTs, connectors.
ChatGPT Enterprise	Custom (typically $50-60+)	SSO, SCIM, audit logs, longer context, enterprise-grade data controls, unlimited usage.
Microsoft 365 Copilot Chat	$0 (with any M365 work account)	Web-grounded chat with enterprise data protection. No in-app actions, no tenant grounding.
Microsoft 365 Copilot	$30 add-on (on top of M365 Business / E3 / E5)	Copilot in Word, Excel, PowerPoint, Outlook, Teams, plus Copilot Chat grounded in your tenant.
Microsoft 365 E7	~$99	E5 + Copilot + Agent 365 + Copilot Cowork. The full agentic stack.

The rough rule of thumb most CFOs we work with end up using: $20-30 per user buys you ChatGPT or Microsoft 365 Copilot. $50+ per user buys you both, or one of them at enterprise grade. $99 per user buys you the agentic Microsoft stack. Pick based on where your team actually works.

If you're still arbitrating between the two ecosystems, our deeper comparison lives here: ChatGPT Enterprise vs Microsoft Copilot vs Gemini and Claude vs ChatGPT for business in 2026.

Option 1: ChatGPT Add-ins Inside Word and Excel

The fastest, lowest-risk way to get ChatGPT into Office is through a Microsoft AppSource add-in. These are official, IT-deployable add-ins that surface ChatGPT as a sidebar inside Word and Excel.

The most widely deployed ones in 2026:

• "ChatGPT for Excel and Word" and "GPT for Excel Word" — third-party add-ins published in AppSource that call the OpenAI API behind the scenes and stream answers directly into the active cell, range, or document.
• OpenAI's own ChatGPT app for Office (where available in your tenant) — adds a ChatGPT pane directly to Word, Excel and PowerPoint, signed in with your ChatGPT Business or Enterprise account.

How to install a ChatGPT add-in (step by step)

1. Open Word or Excel signed in with your Microsoft 365 work account.
2. In the ribbon, click Home → Add-ins (or Insert → Get Add-ins on older builds).
3. In the search box type ChatGPT or GPT for Excel Word.
4. Click Add on the add-in you want, accept the consent screen, and pin it to the ribbon.
5. If your tenant blocks user-installed add-ins (most regulated companies do), have IT deploy it centrally via the Microsoft 365 Admin Center → Integrated Apps.

For Copilot-licensed tenants, the equivalent is just turning on the Copilot pane in the ribbon — no install needed.

What you actually do with it

• In Word: draft a section from a brief, rewrite a paragraph in your house tone, summarise a 30-page contract, translate a clause, expand bullets into a full proposal — all without leaving the document.
• In Excel: generate XLOOKUP / FILTER / SUMIFS formulas from a plain-English description, explain a legacy formula a previous analyst wrote, clean and normalise messy columns, or run "=GPT()" -style functions across thousands of rows for tagging, sentiment, or extraction.
• In PowerPoint: draft slide titles and speaker notes from a Word brief, rewrite a dense slide as a 3-column visual, or generate alt text for accessibility.

If you want the more advanced patterns for Excel + PowerPoint specifically, we already broke those down in Microsoft Copilot for Excel and PowerPoint: The Workflows Nobody Teaches — every prompt pattern in that piece works just as well with a ChatGPT add-in.

Option 2: Connect ChatGPT to OneDrive, SharePoint, Outlook and Teams via the GPT Store

The second integration layer is the more powerful one for knowledge workers: ChatGPT connectors (sometimes labelled "apps" in the GPT store) that let ChatGPT read your Microsoft 365 content directly.

As of 2026, the Microsoft-side connectors available inside ChatGPT include:

• OneDrive (personal and business) — search and read your Word, Excel, PowerPoint and PDF files.
• SharePoint — search across sites, libraries, and pages your account has access to.
• Outlook — search and summarise emails, draft replies, and pull context from threads.
• Microsoft Teams — pull in chats and channel messages where permitted.
• Microsoft Calendar — reason over meetings, prep briefings, and propose times.

Excel, Word and PowerPoint don't have separate connectors — they're accessed through OneDrive and SharePoint, because that's where the files live.

How to connect ChatGPT to your Microsoft 365 tenant

From the ChatGPT desktop or web app:

1. Open a new chat. Click the + (or paperclip / apps) icon in the composer and choose Connect apps (or open Settings → Connectors).
2. Pick OneDrive, SharePoint, Outlook, Teams, or Calendar.
3. Sign in with your Microsoft 365 work account and approve the consent screen. The Microsoft Graph scopes shown should match what your IT team has pre-approved.
4. In any new chat, click + → SharePoint (or OneDrive, Outlook, Teams) to scope the conversation to specific files, sites, or threads.

You can then run prompts like:

• "Summarise the latest budget workbook in the Finance / FY26 SharePoint library and flag any variances over 10%."
• "Find the most recent Q4 pitch deck in OneDrive and extract the customer objections slide as bullet points."
• "Across my last 30 days of Outlook, what are the top 5 unresolved client requests, with the original email links?"
• "Pull the action items from the last #launch-2026 Teams channel discussion and turn them into a Word brief."

If you've ever wondered why people stopped building bespoke Custom GPTs the second connectors launched, this is why — we wrote about that shift in "I haven't used a Custom GPT in 2 months."

Should You Use Copilot Chat, ChatGPT, or Both?

Three honest patterns we see in 2026 across our client base:

• Copilot-only. Regulated industries (banking, healthcare, public sector) usually standardise on Microsoft 365 Copilot because the data never leaves the tenant, governance is centralised, and Copilot Chat is free for everyone else. Our Microsoft Copilot training is built for this profile.
• ChatGPT-only. Smaller, faster-moving teams (agencies, scale-ups, product companies) often prefer ChatGPT Business or Enterprise because the model surface is richer (Projects, Agents, image and voice, GPT store, connectors), and they top up with the OneDrive / SharePoint / Outlook connectors. Our ChatGPT enterprise training covers this stack.
• Both. Most mid-market companies above ~200 employees end up here: ChatGPT Business or Enterprise for power users and creative workflows, Microsoft 365 Copilot rolled out to the rest of the org because it's where they already work.

If you're trying to size this for your own org, our AI governance framework for mid-market companies walks through the policy and licensing decisions in detail.

Security and Governance: Don't Skip This

Connecting any AI tool to OneDrive, SharePoint, Outlook or Teams is a real data decision, not a feature toggle. A few non-negotiables we tell every client:

• Never connect Free or Plus ChatGPT accounts to corporate SharePoint or OneDrive. Use ChatGPT Business, Team or Enterprise — those plans don't train on your data and offer admin controls.
• Scope Microsoft Graph permissions to the minimum. If finance only needs OneDrive and Calendar, don't approve SharePoint or Teams scopes at the tenant level.
• Pre-approve connectors at the tenant level. Use the Entra ID admin consent flow so individual employees can't unilaterally hand over data.
• Audit and rotate. Every quarter, review which connectors are active in ChatGPT → Settings → Connectors, and disconnect anything unused.
• Write a one-page rule of the road. Internal drafts and summarisation: yes. Pasting customer PII or board-only documents into ChatGPT Plus: never. Make it a published policy, not a tribal rule.

A 30-Day Rollout Plan for ChatGPT + Microsoft Office

If you want to move past experimentation this quarter, this is the sequence we use with our enterprise clients.

Week 1 — Decide the licensing posture

Map your population: who needs Microsoft 365 Copilot (everyone in Office daily), who needs ChatGPT Business/Enterprise (power users, marketing, product, R&D), and who's fine on free Copilot Chat. Pick a single primary tool per role; resist letting both run shadow-style.

Week 2 — Wire up the connectors and add-ins

Deploy the ChatGPT add-in for Word and Excel via the M365 admin center for the relevant groups. Have IT pre-approve OneDrive, SharePoint, Outlook and Teams connectors in ChatGPT for the same groups. Verify the consent scopes against your DPIA.

Week 3 — Train a first wave of champions

Pick 10-20 people across finance, marketing, sales, ops and HR. Run a 2-hour hands-on session per group focused on Word / Excel / PowerPoint use cases with real internal documents — not generic demos. This is exactly the format we deliver in our Microsoft Copilot training and ChatGPT enterprise training programs.

Week 4 — Measure and publish

Capture hours saved per role (target: 4-8 hours per person per month), top 3 prompts per department, and one internal case study. Publish the playbook on SharePoint. Then expand to the next 200 people.