What Microsoft 365 Copilot Can See: Client Data Guide for RIAs and Law Offices
Short answer: Microsoft 365 Copilot can only see what the signed-in person already has permission to open. It does not break your permissions — it exposes them. Years of loose SharePoint and OneDrive sharing become instant answers, so client statements, estate documents, or matter files can show up for a coworker who should never have seen them. Clean up sharing first, then turn Copilot on.
What Copilot can see in your Microsoft 365 tenant
Microsoft 365 Copilot works inside the same Microsoft 365 world your staff already use. When someone asks a question, Copilot can draw on that person's email, Teams chats and meetings, OneDrive files, and SharePoint content they are allowed to open. Microsoft's documentation is clear: Copilot only surfaces organizational data the individual user already has at least view permission to reach. See Microsoft's Copilot data, privacy, and security guidance.
Think of it as a permissions mirror. Copilot is not a separate vault with its own rules. It is a fast way to find and summarize whatever that signed-in account can already touch. If permissions are tight, answers stay tight. If permissions are loose, Copilot makes the mess searchable.
Microsoft also states that prompts, responses, and data accessed through Microsoft Graph for Microsoft 365 Copilot are not used to train foundation models. That privacy commitment does not fix oversharing inside your own tenant — permission hygiene is still your job.
How client data ends up in the wrong Copilot answer
Here is the pattern we see in advisor and law offices: nobody "hacked" Copilot. Staff simply shared too widely for years, and Copilot is the first tool that makes every forgotten share easy to discover.
"Everyone" and "anyone with the link" shares
Old habits die hard. A folder shared with "everyone in the company," a default "people in your organization" link that got forwarded, or an "anyone with the link" share that never expired can leave client material reachable by more people than you intended. Re-check defaults against Microsoft's guidance on shareable links in OneDrive and SharePoint and external sharing settings. Copilot does not invent new access; it asks questions against what access already exists.
Old project and matter sites
A closed engagement, a settled matter, or a one-off project site often stays open with the same broad membership it had on day one. Years later, a staff member asks Copilot for "last year's estate plan template" and gets a real client's plan — because that site still includes half the office. Archive or lock those sites before Copilot becomes the office search engine.
Former employees' OneDrive files shared out
Departing staff leave shared OneDrive folders behind. If offboarding only disables the account and never reviews what that person shared, client files can stay reachable. Pair Copilot readiness with a Microsoft 365 offboarding checklist.
External email and prompt injection
A separate risk is content that arrives from outside. Malicious instructions hidden in an email or document can try to steer Copilot. That is not the same as oversharing, but it belongs on the same readiness list. See our post on Copilot and booby-trapped email.
Realistic example: An associate asks Copilot, "Find our standard estate plan template from last year." Copilot returns a finished plan for a living client because that document sat in a team site shared with the whole office. The associate did nothing wrong. The permissions did.
What RIAs and wealth management offices should watch for
For advisors, the sensitive pile is obvious: client statements, account numbers, financial plans, tax packages, and notes that name holdings or life events. Under Regulation S-P, RIAs are expected to maintain safeguards around customer information and to oversee how service providers handle that data. SEC exam priorities for FY2027 keep attention on those safeguards and on how AI shows up in phishing and social engineering — see SEC 2027 exam priorities and what SEC examiners ask your IT provider.
State rules matter too. Texas offices should stay aligned with Texas RIA cybersecurity rules; Colorado advisors with Colorado RIA privacy rules. For the wider stack, see IT and security for financial services. Client documents that belong in a dedicated portal should not live in loose team sites — our companion guide on ShareFile vs SharePoint for client portals explains that split.
What law offices should watch for
For attorneys, Copilot readiness is an ethics and confidentiality problem first. Privileged matter files, conflict-sensitive work product, and sealed or sensitive client records must not surface in another matter team's answers. ABA Formal Opinion 512 addresses generative AI and existing duties of competence, confidentiality, communication, and supervision. It is ethics guidance — not legal advice — but it is a clear signal that lawyers need to understand where client data goes before they put an AI tool on it. See AI ethics and Copilot readiness for law offices, client files in personal inboxes, and IT and security for law offices.
Clean-up checklist before you turn Copilot on
Find and remove company-wide shares on client folders. Search SharePoint and OneDrive for "everyone" / organization-wide access on client, matter, and account folders; tighten to the people who need them.
Review sharing links. Prefer specific-people links; remove stale "anyone" and broad organization links on client material. Reset defaults so new shares are not wide by habit.
Lock down or archive old sites. Close completed matter and client project sites; remove leftover members; archive rather than leave them searchable.
Apply sensitivity labels to client folders and libraries. Labels with the right usage rights limit what Copilot can summarize. Microsoft's Purview guidance on sensitivity labels and generative AI explains how labels and encryption interact with Copilot.
Review guest access. Remove guests who no longer need access; turn on guest expiration where it fits; stop clients from living as perpetual SharePoint guests when a portal is the better path.
Check former-employee OneDrive. During offboarding, reclaim ownership, revoke shares, and move client files out of personal libraries.
Start with a small pilot group. Enable Copilot for a few people who understand client-data rules; review what their answers return before a wider rollout.
Train staff on what not to paste. No pasting client account numbers, full statements, or privileged excerpts into prompts "just to summarize," and pair that with phishing-resistant sign-in for wealth management.
Turn Copilot on in stages, not all at once
A calm rollout looks like this: clean permissions and labels → pilot → review sample prompts against real client content → fix surprises → expand by team. Treat Copilot like a new search index over your existing rights. A planned companion post will cover SharePoint oversharing tools and Restricted SharePoint Search in more depth.
Questions clients and examiners may ask about AI
Write short, factual answers ahead of time:
What AI tools touch our data? Name Microsoft 365 Copilot (and any others), and say they run inside your Microsoft 365 tenant under existing permissions.
Can staff see each other's clients through AI? Explain that Copilot mirrors permissions, and that you reviewed sharing and labels before rollout.
Is our data used to train public AI models? Point to Microsoft's published position that Microsoft 365 Copilot prompts, responses, and Graph data are not used to train foundation models — and still emphasize your own access controls.
Who oversees the vendor? Keep service-provider oversight notes current for Reg S-P conversations; see what SEC examiners ask your IT provider.
How 24uNet helps
24uNet helps RIAs, wealth management offices, and law offices in Texas and Colorado get Microsoft 365 Copilot-ready: permission cleanup, sensitivity labels, guest reviews, offboarding hygiene, and a staged pilot. Start with the Security Baseline checklist or a network security review. Pair that with identity threat detection so those accounts stay safe after Copilot is live.
Frequently asked questions
What can Microsoft 365 Copilot see?
Microsoft 365 Copilot can only see what the signed-in person already has permission to open: their email, Teams chats, and the OneDrive and SharePoint files shared with them. It doesn't override permissions, but it makes every file a user can reach easy to find. If client folders were shared too widely, Copilot can surface them in a coworker's answer.
Can Copilot expose client data at an RIA or law office?
Yes, if sharing is loose. Old "everyone" shares, open matter or client sites, and links that never expired let Copilot pull client statements or privileged documents into answers for staff who shouldn't see them. Cleaning up SharePoint and OneDrive permissions and labeling client folders before rollout closes that gap.
What should we do before turning Copilot on?
Remove company-wide and "anyone" links on client folders, archive or lock down old sites, apply sensitivity labels to client data, review guest access, and check former employees' OneDrive files. Then start with a small pilot group, review what Copilot returns, and expand once results look right.
Comments