Copilot or ChatGPT for a small firm?
Which AI assistant suits a firm already on Microsoft 365.
Decide on where your data lives, not on the model.
Decide on where your work already lives, not on which model is cleverer.
If your email, files and calendar are in Microsoft 365, Copilot works inside them and sits under the contract you already have.
ChatGPT is the stronger general assistant for many tasks, but it reaches your files only through connectors you set up.
The question that decides it
Owners compare these tools on how well they write.
That matters less than where your data sits and what the tool can reach.
An assistant that cannot see your documents saves less time.
One that can see all of them needs your permissions in order first.
| Copilot in Microsoft 365 | ChatGPT on a business plan | |
|---|---|---|
| Reaches your files | Email, Teams and SharePoint, through your permissions | Through connectors you switch on |
| Contract | Your existing Microsoft terms | A separate agreement with OpenAI |
| Training on your prompts | Not used, Microsoft says, when signed in with a work account | Not used by default, OpenAI says |
| Best at | Work inside Outlook, Word and Teams | Drafting, research and analysis on any topic |
Fix your permissions before Copilot
Copilot shows a person anything they can already open.
In most small firms, files sit in folders shared with “everyone” years ago.
Copilot will surface those to anyone who asks the right question, such as salaries, a disciplinary note or a client’s accounts.
Before you switch it on, review who can open what in SharePoint and OneDrive.
Tighten the folders that hold personal or client data.
That review is worth doing anyway.
When ChatGPT is the better fit
- Your firm runs on Google Workspace, or on a mix of tools rather than Microsoft.
- The work is drafting and thinking, such as proposals, research and explaining a rule, more than finding things in your own files.
- You want one tool everyone uses the same way, whatever software they have.
Whichever you choose
Put everyone on company accounts, sign the processing agreement and confirm training is off.
Then write one page saying which tool staff may use for what.
Our guides to client information in AI tools and a small-firm AI policy cover both steps.
Neither tool decides which work to automate.
That comes from your own processes, and what to automate first shows how to find it.
Frequently asked questions
Is Copilot safer than ChatGPT for client data?
Neither is safe by default.
Both offer business terms that keep prompts out of training.
Check the plan you are on.
Can we use both?
Yes, but write down which tool staff may use for which work.
Two tools double the checks.
What should we fix before turning on Copilot?
File permissions.
Copilot can surface anything a person can open, including files shared too widely.
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