Copilot vs ChatGPT: Which to Pick If You're on Microsoft 365

Copilot and ChatGPT differ mostly in where they work. Copilot lives inside your Microsoft 365 apps and can read your work data, while ChatGPT is a separate app that's stronger on its own.

Under the hood they're closer than most people think. Microsoft's Australian Copilot pricing page says its paid plans run on the "latest OpenAI models: GPT-5.X". That's the same company that makes ChatGPT. So the choice is less about which is smarter and more about where your staff already work.

Copilot's edge is what Microsoft calls Work IQ. It means the AI can search your emails, meetings, chats and files to answer you. ChatGPT starts with what you paste in or connect to it. For a business that already runs on Outlook and Teams, that difference decides most of the choice.

Paid Copilot can answer questions from your own mail, meetings, chats and files. It's built into the apps where that work sits.

Microsoft's licence comparison page spells out the split. Without a paid licence, Copilot's work data reasoning is "Limited (uploaded files)". With one, it's "Full (meetings, emails, chats, files, and more)". In Teams, the line is firmer. Microsoft's Teams chat help page says a user "must have a Copilot license" to ask Copilot questions in a chat.

Excel is the weak spot. The Australian Government's Copilot trial evaluation found "Poor Excel functionality and access issues in Outlook hampered use". That trial ran from January to June 2024, so Copilot has changed since. Still, test it on your own spreadsheets before you trust it with them. Outlook and Teams are where Copilot earns its seat.

ChatGPT does more on its own. It has stronger image tools, deep research and newer models than Copilot gives most small businesses.

OpenAI's pricing page lists Plus with "Advanced reasoning models with GPT-6", plus deep research, image creation and scheduled tasks. Copilot's paid plans list GPT-5.X. If your work is writing ads, making social images or researching a new market, ChatGPT usually gets you further in fewer steps.

ChatGPT also isn't locked out of Microsoft. The Business plan says it can "Connect to Google Workspace, Slack, GitHub, Microsoft 365, and more", with "No training on your business data by default". It can also search live pages, which is how ChatGPT searches the web for current answers. What it can't do is sit inside Outlook and read the thread you're looking at.

For a Microsoft 365 business, Copilot wins on your own work data and ChatGPT wins on range. Every price below is in Australian dollars, checked on 2 October 2026.

Copilot is the better pick when the job starts in your inbox, calendar or files. ChatGPT is the better pick when the job starts from a blank page.

Copilot Business costs A$26.91 a user a month on a yearly plan, and ChatGPT Business costs A$28 a seat a month billed yearly. Both prices come with fine print.

Microsoft's Copilot price is a promotion that runs from 1 July to 31 December 2026, and it applies to the first year only. The full price is A$31.40, or A$37.68 on a monthly plan, and none of these include GST. ChatGPT Business is A$35 a seat on a monthly plan. For one person, ChatGPT Plus is A$30 a month and Go is A$13.

Doing nothing has a price too. Say five staff each get a Copilot seat and a ChatGPT Business seat.

If both tools end up writing the same emails, half of that buys nothing. What manual processes cost is often the bigger number, but overlapping seats are the easiest leak to see.

Yes, Copilot Chat comes free with most Microsoft 365 business plans. So you can test Copilot before you pay for a single seat.

Microsoft's business plans page says Copilot Chat "is available at no additional cost" to users with an eligible subscription. Even Business Basic, at A$10.50 a user a month, includes web-grounded chat, writing help and data analysis. Copilot in Outlook is included with or without the paid licence, per Microsoft's own licence table.

Claude is a third option that suits long writing, careful thinking and building workflows. It's not part of Microsoft 365, so it works best outside your inbox.

UnderCurrent Automations uses Claude today. We run our own work and the workflows we build on it. We're open to changing model, but Claude works for us, and switching every month wastes time. Our guide to using Claude in your business covers the setup if you want to try it.

The same rule applies to all three. Pick by the job, not the brand. Copilot is strongest inside Microsoft's apps, ChatGPT is the strongest all-rounder, and Claude is strong for building. Before you trust any of them on recent events, check its knowledge cutoff, because a model can be months behind the news.

A chat tool only helps when someone stops to ask it something. A workflow does the job without being asked, and that's where the real hours come back.

Before he started UnderCurrent Automations, our founder worked in a sales job. Prospecting, lead research and first email drafts were the repeat work of every day. So he built a workflow that handled all three in one pass.

It saved him three hours a day, which is 15 hours across a five-day week. That's the gap between picking a chat tool and fixing the job. Copilot and ChatGPT both make each step faster, but AI automation removes steps. When it's fixed, the routine work runs on its own and a person checks the output. For a business on Microsoft 365, that usually means Copilot for the inbox and a workflow for the repeat jobs.

Choose Copilot if your team lives in Outlook, Teams and SharePoint. Choose ChatGPT if your work starts from a blank page or crosses many apps.

Choose Copilot if most of your questions are about your own emails, meetings and files. You'll get answers where you already work, with no new login. Choose ChatGPT if you make images, run research or use Google tools beside Microsoft. Some teams need both, but buy the second only after the free test proves a gap. Either way, staff still need to learn to ask well, which is where AI training for small business pays off.

UnderCurrent Automations builds workflows on Claude for small businesses across Australia. If one job eats your week, get in touch and we'll map it into a workflow. The first chat costs nothing, and it'll show which tool suits that job.

• What is an AI agent for business, what changes when AI can take steps on its own.
• The simplest small business automation tasks, good first jobs to hand to a workflow.
• What is business process automation, how a workflow differs from a chat window.