Copilot security risks are quietly becoming one of the biggest blind spots in UK offices right now. Microsoft has made it easy to switch on, easy to love, and genuinely useful for drafting emails or summarising meetings. What’s less obvious is that Copilot doesn’t create new information, it surfaces what’s already sitting in your systems. If your permissions are a mess, Copilot won’t fix that. It’ll just make the mess a lot easier to find.
I’ve covered the mechanics of this in more detail elsewhere, including a full breakdown of Copilot security considerations and how AI tools at work can end up leaking business data, which I unpack in this piece on AI at work. This article is the shorter version, the bit you can read before your next leadership meeting.
Why copilot security risks are different from normal software risks
Most software does one job in one place. Copilot doesn’t work like that. It reads across your emails, your SharePoint files, your Teams chats, and your calendar, then stitches the results together into an answer. That’s the whole point of it, and it’s genuinely clever.
The problem is that Copilot inherits whatever access the person using it already has. If someone in finance can technically open a folder containing HR salary data because a permission was never tidied up, Copilot can now find that folder for them in seconds, without them even having to know it existed. The tool isn’t misbehaving. It’s doing exactly what it’s told, using access that should never have been there in the first place.
The permissions problem nobody fixed before switching it on
Here’s the uncomfortable truth. Most organisations have permission structures that grew organically over years. Someone left the company and their old team folder never got locked down. A project shared drive was opened up to “everyone” because it was faster than sorting out individual access. Nobody audited it because, before Copilot, nobody could search it all at once anyway.
Copilot changes that overnight. It turns years of accumulated permission sprawl into a single, fast, conversational search engine. If your access controls were loose before, they’re now a live risk, and the fix isn’t turning Copilot off, it’s finally doing the access review that should have happened years ago.
Sensitive data turning up in places it shouldn’t
A common scenario I see is a well-meaning employee asking Copilot to summarise “everything about Project X” for a client update, and getting back a summary that includes an internal pricing strategy document or a draft contract that was never meant to leave the legal team. Nobody did anything malicious. The document was technically accessible, so Copilot used it.
This is where copilot security risks stop being theoretical and start showing up in real conversations, real client emails, and real compliance headaches. The fix isn’t complicated, but it does take effort: proper data classification, sensible labelling, and permissions that actually reflect who should see what.
Shadow AI use makes this harder to control
Even organisations that haven’t officially rolled out Copilot are often dealing with staff who’ve enabled it themselves, or who are using personal AI accounts to process work documents because it’s quicker than asking IT. This is sometimes called shadow AI, and it’s a natural extension of shadow IT, the practice of using unapproved tools because the approved ones are too slow or too restrictive.
The risk here is that you lose visibility entirely. At least with an officially deployed Copilot, your IT team can see usage patterns and apply some controls. With unofficial use, you’ve got sensitive company data going through tools nobody signed off on, with no audit trail and no way to know what’s been shared.
What actually reduces copilot security risks in practice
The good news is that none of this requires banning AI tools outright, which rarely works anyway and just pushes the problem underground. What it requires is doing the boring groundwork first.
Start with an access review. Work out who can actually see what, and strip back anything that’s been left open out of convenience rather than necessity. Pair that with clear data labelling so sensitive files are marked as such before Copilot ever gets near them. Then put a simple, honest policy in place that tells staff what they can and can’t feed into AI tools, written in language people will actually read rather than a ten-page document nobody opens.
Finally, test it. Ask Copilot the kind of question a curious or careless employee might ask, and see what comes back. If something surprises you, that’s exactly the gap you needed to find before someone else did.
If you want a proper look at how Copilot might be exposing your business right now, my breakdown of Copilot security considerations is the natural next read.
