Copilot Doesn't Ask Twice: The Permission Sweep to Run Before You Switch It On

There's a moment in every small-team AI rollout where someone says the reassuring thing: "don't worry, it only shows people what they already have access to." That sentence is technically true and practically useless. It's a bit like saying the office is secure because the front door is locked, while the back door has been propped open since 2019 and nobody's mentioned it.

Microsoft 365 Copilot and Google's Gemini for Workspace don't create permissions. They inherit them. Every SharePoint site with "Everyone except external users" ticked, every shared drive where the whole company got Editor by default, every folder someone opened up in a hurry during a merger — the assistant can now read all of it, summarise it, and hand it back to whoever asks nicely.

Which is fine, until you remember what's actually in there. Redundancy consultations. Salary bands. A disciplinary letter from three HR managers ago. The spreadsheet where the finance director tracks the acquisition nobody's been told about yet.

So before you press the button, do the sweep.

First, find out what's actually shared

You can't fix what you haven't looked at. The good news is that both platforms have reports for this, and neither requires a consultant.

In Microsoft 365, go to the SharePoint admin centre and pull the site permissions report, then the sharing report. In Google Workspace, the Drive audit and the "Shared externally" view under Drive settings will give you the same picture. Export both to a spreadsheet. You're looking for three things: sites or drives with broad internal sharing, anything marked as publicly linkable, and any folder where "anyone with the link" is still set to Viewer or Editor.

You will find things you don't recognise. That's normal. Small teams accumulate ghost sites the way kitchens accumulate mismatched mugs — someone left, someone renamed a project, nobody tidied up.

The restrict-first list

Don't try to fix everything in one afternoon. You'll get bored, and worse, you'll break something people rely on. Instead, pick a short list of things to lock down before the assistant goes anywhere near them.

People data. HR folders, anything containing NI numbers, salary spreadsheets, right-to-work documents, occupational health notes. If it's in a site called "HR" and everyone in the company is a member, that's your first fix.

Commercially sensitive material. Board packs, pricing models, contract negotiations, anything with the word "confidential" in the filename. Special category stuff under UK GDPR — health data, ethnicity monitoring, union membership — should not be readable by a general-purpose chatbot that answers whatever it's asked.

Client and customer data. If your team handles personal data for clients, remember that Copilot can surface it in response to a query. That's still you processing it, and it's still covered by your lawful basis and your contract.

Old projects. Folders from 2018 that nobody owns are the classic over-share. Archive them, restrict them, or delete them. Any of those is better than leaving them wide open for a chatbot to quote back.

Practice saying this out loud: "If I wouldn't email it to the whole company, the assistant shouldn't be reading it out either." That's the whole test.

A prompt policy that fits on one side of A4

You don't need a forty-page governance document. You need something people will actually read, pin to the intranet, and remember when they're typing a question at 4:55pm on a Friday.

Keep it to six lines. Something like:

1. Don't paste personal data about customers, colleagues or applicants into a prompt unless you'd be happy for it to appear in a team meeting.
2. Don't ask the assistant to summarise anything you wouldn't hand to the whole team.
3. Check outputs before you forward them — the assistant doesn't know which supplier quote is current.
4. Never use it to make decisions about people (hiring, performance, discipline) without a human reviewing the output.
5. If you're unsure whether something's in scope, ask before you paste.
6. Report anything that looks wrong, odd, or overly revealing to the person who owns the rollout.

That's it. Sign it off, share it, mention it in the all-hands. Under UK GDPR you'll also want to note the processing in your records and think about whether a DPIA is needed — for most small teams doing internal productivity work with Copilot, a short DPIA-lite note is plenty, but if you're feeding client personal data through it, be more careful.

The bit people forget

The assistant is only as well-behaved as the permissions underneath it. You can write the loveliest prompt policy in the world, and it won't stop a chatbot from summarising a confidential document that fifty people could already open. The controls that matter are the boring ones: who's a member of which site, which folders are shared with "everyone", and whether anyone has actually looked at that list since it was set up.

So schedule a repeat. Twice a year is enough for most small teams. Pull the report, spot the new overshares, and fix them. Ten minutes of tidying beats a very awkward conversation later about how the redundancy plan ended up in a summary someone asked for on a Tuesday.

The chatbot isn't the risk. It's just the thing that finally makes the risk visible. Which, if you squint, is a bit of a gift — it's the cheapest permission audit you'll ever get, and it comes with a compelling reason to actually do it.