Copilot data readiness is not a setting you switch on. Copilot returns only content the person asking could already open, so your data is ready for it when the people who can open each site, library and file are the people who should. Every control in this article either moves an estate towards that state or holds the line while the work is done.
That framing decides what gets bought and in what order. Microsoft’s own deployment guidance now starts with remediating oversharing, treats its containment controls as interim, and puts the durable label and DLP guardrails in a second stage. This article sets out the controls Microsoft documents as of 26 October 2026: what each does to Copilot, what licence it needs, whether Microsoft still marks it as preview, and where it stops. The scope of the assessment itself is covered in what a Copilot readiness assessment checks.
Microsoft’s newer SharePoint pages call the product Microsoft Copilot and its Purview pages still say Microsoft 365 Copilot. This article says Copilot for both.
What Copilot can reach, and what that makes “ready”
Microsoft’s data, privacy and security page for Copilot states the rule plainly: Copilot “only surfaces” data “to which individual users have at least view permissions”. Grounding runs inside the identity of the person asking. Copilot does not widen anyone’s access.
What it changes is how easily existing access is used. A file buried in a forgotten library was protected, in practice, by nobody knowing it was there. Microsoft’s Purview guidance for AI apps puts it in one line: “generative AI amplifies the problem and risk of oversharing or leaking data”.
Two consequences follow.
First, the controls that matter most are the ones that change who can open something. Controls that change only what Copilot may process, such as DLP for Copilot and the usage rights inside a label’s encryption, act on whatever exposure is left. Microsoft’s blueprint sequences them that way: remediate access first, then add guardrails.
Second, readiness has a boundary. Copilot can also use the file a user has open “regardless of where that file is stored”, including local disks and USB sticks (Purview considerations for Copilot). The user already holds that file, so data readiness is about the tenant’s content estate, not every copy of a file.
In our view, Copilot data readiness should be declared site by site, for the business-critical sites first, rather than tenant-wide. The controls work that way too: restricted access control, Restricted Content Discovery and site access reviews each apply to one site at a time.
Readiness in this sense is also not what Microsoft’s Copilot readiness report measures. That report, in the Microsoft 365 admin center, “helps you identify which users are technically eligible for Copilot”. It says nothing about who can open what.
Content becomes readable by most of an organisation through four routes, and Microsoft’s reports find each in a different place.
| Route to broad access | How it usually arises | Where Microsoft surfaces it |
| Everyone except external users (EEEU) or Everyone, granted on a site, folder or file | Public Microsoft 365 group sites add EEEU to Members by default, and the People Picker offers EEEU by default | Site permissions report, special groups report, EEEU activity report |
| Broken inheritance | Unique permissions on a folder or file inside a site that is otherwise correctly restricted | Site permissions report, Content Management Assessment |
| Groups that grew | A security or Microsoft 365 group whose membership now covers most staff | Site permissions report, which expands every group to unique users |
| Sharing links | Anyone and People in your organization links once they have been redeemed, and Specific people links that name large groups | Sharing links activity report, link counts in the site permissions report |
In the tenants we have worked on, the two routes we meet most often are EEEU on public group sites and groups that grew.
Microsoft’s blueprint, as it reads today
Microsoft’s oversharing blueprint has been replaced. The old URL now redirects to Secure and govern Microsoft Copilot: Foundational deployment guidance, dated 6 May 2026 and updated 3 November 2026, which organises the work into three pillars: remediate oversharing, set up guardrails, and meet regulations. The step-by-step version, Configure a secure and governed foundation for Microsoft Copilot, now redirects to the same page.
Remediate oversharing has three stages. Identify high-risk sites with Purview’s data risk assessments and the SharePoint Advanced Management Content Management Assessment, which Microsoft says finds sites with “oversized audiences, EEEU usage, broken inheritance, inappropriate sharing”, and those that are inactive or ownerless. Apply interim protections, meaning Restricted Content Discovery and DLP for Copilot. Then fix access: apply site sensitivity labels, remove excessive or anonymous access, run site access reviews, correct broken inheritance and confirm site ownership. The stage ends with an instruction that is easy to skip: “Remove interim Copilot protections once access and permissions are remediated”.
Set up guardrails stops new oversharing at creation. Microsoft asks for restricted access control by default on business-critical sites “at provisioning time”, and to “Disable or restrict use of Company-wide sharing groups and Sharing with Anyone link at the tenant level”. Site sensitivity labels are to be required at provisioning, with auto-labelling, default labels and DLP for Copilot layered on top.
Meet regulations covers audit, retention and eDiscovery for Copilot interactions, and data hygiene: inactive site policies, retention and deletion, and Microsoft 365 Archive, which is pay-as-you-go and billed per gigabyte archived (setup page).
Two details are easy to miss. The Content Management Assessment runs on all sites across the organisation, not a sample. And Restricted SharePoint Search is retiring: Microsoft’s Restricted SharePoint Search page says new enablement has been blocked since 31 July 2026. On licensing, the blueprint’s PDF has separate checklists for E3 and E5 customers, and marks which steps need Copilot, E3, or E5 or the Microsoft Purview Suite.
Permission hygiene in SharePoint and OneDrive
Start from the defaults, because they are open.
EEEU is the first thing to close. Microsoft’s page on the special groups report is direct: “Unresolved EEEU permissions are a top oversharing risk. Content shared with these groups is visible to every internal user, and it surfaces directly in Microsoft Copilot search results”. Two defaults keep feeding it. The People Picker shows EEEU unless an administrator sets ShowEveryoneExceptExternalUsersClaim to false, which Set-SPOTenant documents as true by default. And on public Microsoft 365 group sites, “By default, the Everyone except external users claim is added to the Members group”, according to Microsoft’s troubleshooting article. Hiding the claim in the picker governs what users can choose next. Finding the grants that already exist is the job of the reports below.
Broken inheritance is the exposure a site-level review misses. A site can be locked down while a folder inside it carries much wider permissions of its own. The site permissions report counts that item-level access when it calculates who can reach a site, which is why it is the baseline.
Sharing links are a smaller exposure than they look, and it matters why. Microsoft’s page on shareable links states: “Creating a People in your organization link doesn’t make the associated file or folder appear in search results or make it accessible through Copilot.” A link has to be redeemed, by clicking it, before it grants anything. Sending one from SharePoint, OneDrive, Outlook or a Teams chat redeems it automatically for individual recipients, up to 100, but not for group recipients or Teams channel posts. So a link’s reach is the people it actually reached, while an EEEU grant reaches everyone at once. Specific people links are the exception to the redemption rule: the same page says they make the item appear in search and accessible through Copilot “for all user and security group members who are added to the sharing link”, so one sent to a large security group behaves like a grant. On Microsoft’s own description, that argues for closing EEEU and Everyone grants, and links that name large groups, before chasing individual links.
The default link type is the cheap guardrail. In the sharing settings, Microsoft describes Specific people as the option that is “most restrictive and impedes broad internal sharing”. Anyone links can be set to expire and limited to view only.
Owner-led or central remediation
Microsoft documents two ways to remove the access the reports find, and the choice between them is a design decision.
The owner-led route is the site access review. An administrator sends site owners a review tailored to the finding, because, in Microsoft’s words, “Compliance reasons prevent IT administrators from accessing file-level or item-level details.” Reviews work for SharePoint sites only, up to 100 at a time from the report’s web view, and up to 1,000 a month from the site permissions report. Microsoft’s prerequisite is that site owners are available to respond, so an ownerless site cannot be reviewed this way until it has an owner, even though the blueprint lists ownership after the reviews.
The central route is the special groups report. It lists each item that EEEU or Everyone can reach, apart from system files and groups, so that, as Microsoft puts it, oversharing can be fixed “through scripting, rather than depending on individual site owners”. It cannot run until a site permissions report has been generated at least once. It needs the SharePoint Advanced Management Administrator role, assigned by a Global Administrator, because “Standard SharePoint administrators and Global administrators can’t view file properties across sites they don’t own.” Microsoft’s prerequisites page lists that role as able to view names, paths and URLs across SharePoint content and remove permissions at scale, so who holds it is worth deciding deliberately.
SharePoint Advanced Management, feature by feature
Licensing first. Once at least one user, not necessarily an administrator, is assigned a Copilot licence, SharePoint administrators get the Advanced Management features that support a Copilot deployment (features in Copilot licences). The prerequisites page adds two other routes: the Plan 1 add-on with SharePoint K, P1 or P2, and Microsoft 365 E7.
Three caveats. Restricted site creation by apps needs Plan 1 even with Copilot. The sensitivity label report “Requires E5 or G5”. And an E5 tenant without Copilot or Plan 1 gets only part of the data access governance reports: its administrators “can’t view or use the other SharePoint Advanced Management features”, there are no snapshot reports or remedial actions, and the activity reports return up to 10,000 sites.
One tension to check. The prerequisites page lists the base subscriptions as Office 365 E3, E5 or A5, Microsoft 365 E1, E3, E5 or A5, and the government clouds. Business plans are not on it, although the Copilot features page refers to business customers, so a Business Premium tenant should confirm with Microsoft first.
Status. None of the features below is marked as preview on Microsoft’s pages as checked on 26 October 2026.
| Feature | What it does for Copilot data readiness | Limits worth knowing |
| Content Management Assessment | Runs five reports across every site: inactive (no activity in 180 days), ownerless or single-owner, broken inheritance, EEEU and permissive sharing links | Takes 2 to 72 hours depending on tenant size; Microsoft suggests rerunning it every 30 days; it changes nothing without an administrator |
| Site permissions report | The baseline of who can reach every SharePoint and OneDrive site, with groups expanded to unique users | First run takes up to 5 days whatever the tenant size, later runs within 24 hours, once every 30 days; the web view shows the top 100 sites, the CSV up to 1 million; excludes archived and NoAccess sites |
| Special groups report | Every item EEEU or Everyone can reach, for scripted clean-up | Needs a site permissions report first; SharePoint Advanced Management Administrator role; 1 million rows; covers SharePoint and OneDrive together; every 30 days |
| Sharing links and EEEU activity reports | What was shared broadly in the last 28 days | Microsoft suggests running them monthly |
| Sensitivity label report | Sites holding files with a chosen label, with their site policies | E5 or G5; SharePoint only, not OneDrive |
| Site access reviews | Delegates review of a finding to the site owner | SharePoint only; 100 sites from the web view, 1,000 a month from the permissions report |
| Restricted access control | Limits a site to members of up to 10 groups; search and Copilot honour it | Users need both permission and group membership; channel sites are configured separately |
| Restricted Content Discovery | Hides a site from organisation-wide search and Copilot discovery | Does not change permissions; SharePoint only; over 500,000 items can take more than a week |
| Site lifecycle policies | Ownership, inactive site and attestation policies keep sites owned, current and reviewed | Simulation and active mode are both included with Copilot |
Restricted access control: what breaks
Restricted access control is the strongest control in the set, because it changes who can open a site rather than who can find it: “Users not in the specified group can’t access the site or its content, even if they had prior permissions or a shared link.” Search and Copilot honour it, after a delay that grows with the number of items in the site.
Three details cause most of the surprises. Adding someone to the control group does not give them access; they need an existing permission as well. Shared and private channel sites are separate site collections, so a policy on the parent team’s site does not cover them. And by default, sharing a protected site’s content with someone outside the group is still allowed; blocking it is opt-in.
Restricted Content Discovery: what changed
Restricted Content Discovery hides a site from organisation-wide search and Copilot discovery without changing who can open it. Microsoft calls it “a temporary governance control”, and the case for dating its removal is made in what Purview can actually stop Copilot doing.
What changed is on Microsoft’s page, updated on 11 October 2026: it now says the control limits discovery “including recently interacted files”, while Microsoft’s licensing page still describes an exception for recent interaction, so test which behaviour your tenant shows. Microsoft also cautions that heavy use makes search and Copilot answers less complete.
Where OneDrive falls through
OneDrive appears in the reports but has fewer containment controls. Restricted Content Discovery, site access reviews and the sensitivity label report do not cover it. Restricted access control does, either through security groups or for a specific user’s OneDrive (features in Copilot licences), and the site permissions and special groups reports both include it.
So an overshared OneDrive has no hide-it-while-we-review option. The fix is the permission change itself, or restricted access control, and the plan should name who makes it.
Sensitivity labels: what they change for Copilot
A label on a file does not change its SharePoint permissions. Labels change three other things.
Encryption decides whether Copilot can return the text. Copilot needs the EXTRACT usage right, as well as VIEW, to display or summarise the text of encrypted content; with VIEW alone it can only offer a link. The Editor permission level, previously called Co-Author, includes it, and Microsoft’s considerations page says content protected that way “can be returned by Copilot and agents”. Microsoft’s own default label Confidential \ All Employees encrypts with Co-Author rights for all users and groups, so Copilot can still summarise a file under it for any employee who can open it. Encryption is not Copilot exclusion; the difference is set out in the Purview article. Labels must also be enabled for SharePoint and OneDrive, or, according to Microsoft’s Purview guidance for AI apps, the encrypted files Copilot can access “are limited to data in use from Office apps on Windows”.
Site labels are a permissions guardrail, not a Copilot control. A label on a site or team is not inherited by its items, and Copilot will not display it. What a site label can do is set the site’s privacy, external sharing, access from unmanaged devices and, through PowerShell, its default sharing link type (container label page). That is why the blueprint asks for site labels at provisioning.
Copilot output inherits labels. Microsoft notes that “an inherited label when you create new content will replace a lower priority label that was manually applied”, and the Purview service description lists inheritance for E3 with a Copilot licence.
Manual labelling comes with E3, and inheritance with E3 plus a Copilot licence. Automatic labelling, default labels for document libraries, and the DLP control that stops Copilot processing labelled files and emails sit in the E5 tier, such as Microsoft 365 E5 or the E5 Information Protection and Governance add-on; Microsoft’s auto-labelling page confirms auto-labelling is not in E3 or Business Premium.
The starting point matters more than the licence. In our assessments, around 90% of estates have no sensitivity labels set at all. For most organisations, the label-based Copilot controls have nothing to act on when the first licences arrive. The permission work does not depend on labels, and Microsoft’s sequence does not ask it to wait for them. A labelling programme can follow, as set out in our article on rolling out sensitivity labels.
The minority are the opposite case. Microsoft states that default labels and policies “are now automatically created for new customers who have an eligible license”, so some tenants already have a taxonomy nobody chose. Our position is the one we hold for labelling generally: adopt Microsoft’s default taxonomy, do not inherit it. The names and sublabels are a sound start, but review what exists, decide explicitly what to keep, and turn off what you have not yet decided about. Copilot raises the stakes, because an unreviewed label already decides, through its encryption settings, whether Copilot can return a file’s text, and which label Copilot’s own output carries.
DLP for Copilot, briefly
For data readiness, one DLP control matters most: the policy that stops Copilot processing files and emails carrying chosen sensitivity labels. Microsoft’s blueprint uses it twice, as an interim protection while sites are remediated and as a durable guardrail afterwards. Microsoft’s DLP location for Copilot builds it on the sensitivity labels condition, and it sits in the E5 tier.
That is where the 90% figure bites. In an estate with no labels, the DLP half of Microsoft’s interim protection has nothing to match, which leaves Restricted Content Discovery as the interim control that works without them. The other DLP controls for Copilot, their preview status and what they cannot stop are set out in what Purview can actually stop Copilot doing, and designing the rules in Purview DLP policy design.
Keeping the estate ready
Copilot data readiness does not stay achieved. New sites, groups and links arrive daily, which is why the second pillar of Microsoft’s blueprint is about defaults at creation rather than another clean-up.
Microsoft’s own cadence is a reasonable baseline: snapshot reports quarterly, activity reports monthly and the Content Management Assessment every 30 days. Between runs, the ownership and inactive site policies in active mode notify owners when a site falls outside the criteria you set. Purview’s view of AI activity is a separate tool with its own blind spots, set out in what DSPM for AI shows and cannot see.
The remediation is a project. Running the reports every month for as long as Copilot is licensed is not, which makes ownership of the cadence an operating model question, for the reasons in managed service vs project delivery.
Where to start
- Confirm the licence position. One assigned Copilot licence unlocks the Advanced Management features; check your base subscription is on Microsoft’s list, and whether you need E5 for the label report and label-based DLP.
- Start the slow reports first. Run the Content Management Assessment and the site permissions report as soon as the first Copilot licence is assigned, because the first permissions report can take up to five days and the special groups report cannot run without it.
- Close EEEU. Hide the claim in the People Picker, review public group sites, and run the special groups report to find existing grants.
- Fix ownership before access reviews. Reviews go to owners, so ownerless sites need owners first.
- Decide owner-led or central remediation, and if central, name who holds the SharePoint Advanced Management Administrator role.
- Protect business-critical sites with restricted access control, and use Restricted Content Discovery only for sites still under review, with a date for removing it.
- Then labels and DLP, starting from what already exists in the tenant.
Veratas builds and runs security and compliance controls across Microsoft 365, including the Purview information protection layer, and designs and migrates SharePoint estates for secure collaboration and content control. If Copilot licences are on order and nobody has looked at who can open what, talk to our team. The site permissions report becomes available once the first Copilot licence is assigned, and its first run can take five days, so the plan is worth having before the licences land.
Frequently asked questions
What is Copilot data readiness? It is the state in which the people who can open each site, library and file are the people who should, because Copilot only returns content a user already has at least view permission for. Microsoft’s deployment guidance makes remediating oversharing its first pillar, ahead of the durable guardrails.
Can Copilot see content that users are not allowed to open? No. Copilot only surfaces data the individual user has at least view permission for. The risk is that many users already have permission to far more than anyone intended, through EEEU grants, broken inheritance, oversized groups and sharing links.
Do we need to buy SharePoint Advanced Management for Copilot? Not usually. Once one user is assigned a Copilot licence, on one of the base subscriptions Microsoft lists, SharePoint administrators get the Advanced Management features that support Copilot, including restricted access control, Restricted Content Discovery, the permission reports and site access reviews. Restricted site creation by apps still needs the Plan 1 add-on, and the sensitivity label report needs E5 or G5.
Is there a Copilot readiness test? Not a single one. Two Microsoft tools answer different halves of the question. The Copilot readiness report in the Microsoft 365 admin center identifies which users are technically eligible for a licence. The Content Management Assessment in SharePoint Advanced Management tests the data: five reports across every site covering inactive and ownerless sites, broken inheritance, EEEU and permissive links, taking 2 to 72 hours.
Do we need sensitivity labels before rolling out Copilot? Not to start. A label on a file does not change its SharePoint permissions, and in our assessments most estates have none, so the permission work comes first. Labels add processing controls later, and automatic labelling and the DLP control that stops Copilot processing labelled files need E5-tier licensing.
Azure and Business Intelligence Architect with 17+ years of experience delivering cloud data and analytics solutions. Focus areas include Azure data platforms, ETL and ELT architecture, and enterprise BI on Microsoft Azure.