Microsoft 365 Access Review Checklist for SMEs

As organisations grow, access to Microsoft 365 often becomes more complicated than expected.

New staff join, roles change, teams are created, external guests are invited, shared mailboxes are added and administrative access is granted to solve immediate problems. None of these actions are unusual on their own. The risk appears when access is not reviewed afterwards.

Over time, users may retain permissions they no longer need. Former staff may still have access to shared resources. External guests may remain in Teams or SharePoint sites long after a project has finished. Administrators may hold broad access simply because it was easier than assigning a more limited role.

For SMEs, access reviews do not need to become a large compliance programme.

The aim is to create a practical, repeatable way to check who has access, why they have it and whether that access is still appropriate.

This Microsoft 365 access review checklist helps small and growing organisations review high-impact permissions first, define clear ownership and build a manageable monthly governance routine.

What is a Microsoft 365 access review?

A Microsoft 365 access review is a structured check of user permissions, administrator roles, group memberships and collaboration access.

The purpose is simple:

• Confirm that users still need the access they have
• Remove access that is no longer required
• Identify permissions with no clear owner
• Reduce unnecessary admin privileges
• Review external sharing and guest access
• Keep collaboration secure without making it difficult to work

An access review should not only focus on individual user accounts.

It should also include shared mailboxes, Teams, Microsoft 365 groups, SharePoint sites, guest users, privileged roles and access granted to external suppliers.

For many SMEs, the biggest challenge is not technology. It is ownership.

When nobody is clearly responsible for deciding whether access should continue, permissions often remain in place by default.

Define access ownership first

Access reviews are most effective when ownership is explicit.

Before checking permissions, agree who is responsible for approval decisions in each area. This avoids the common situation where IT knows how to remove access but does not know whether the user still needs it.

A simple ownership model could look like this:

The owner does not need to manage the technical changes themselves.

Their role is to confirm whether access is still needed and whether it remains appropriate for the person’s role.

This creates accountability without adding unnecessary complexity.

A clear ownership model also makes it easier to respond when something changes. If a user leaves, changes department or begins working on a different project, the right person knows who should approve the access update.

Start with high-impact permissions

Not all permissions carry the same level of risk.

A user having access to a low-risk internal Team is different from a user holding Global Administrator access or being able to manage company-wide security settings.

For this reason, access reviews should begin with the permissions that could have the greatest impact.

A sensible review order is:

1. Global and administrative roles
2. Privileged access to sensitive systems
3. Shared mailboxes and delegated access
4. Microsoft 365 groups and Teams ownership
5. SharePoint site permissions
6. External guest access
7. General group memberships and collaboration permissions

This approach helps SMEs focus effort where it matters most.

You do not need to review every permission manually every month. Start with the highest-risk areas, then work through collaboration permissions on a planned schedule.

Review global and administrative roles

Administrative access should be reviewed first.

Microsoft 365 includes different administrative roles for identity, Exchange, Teams, SharePoint, Intune, security and compliance. These roles can make changes that affect many users, devices and services.

A practical administrator review should ask:

• Who has Global Administrator access?
• Does each person still need that level of access?
• Could a more limited admin role be used instead?
• Are external IT suppliers still assigned admin roles?
• Are former employees or inactive accounts still listed?
• Are emergency access accounts documented and protected?
• Are administrator accounts separate from standard daily-use accounts?
• Is multi-factor authentication enforced for all privileged users?

The goal is to reduce standing risk.

Where possible, avoid giving broad permanent access simply because it may be useful in the future. Assign the lowest level of privilege needed for the task.

For example, someone responsible for Teams administration may not need Global Administrator access. Someone managing mobile devices may only require an Intune-related role.

The fewer people with broad administrator access, the easier the environment is to manage and review.

Review shared mailboxes and delegated access

Shared mailboxes are useful for areas such as enquiries, accounts, HR, sales, support or operations.

However, access can grow over time without being reviewed. Staff may keep access after changing roles, temporary cover may become permanent, or there may be no clear owner for the mailbox.

For each shared mailbox, review:

• Who owns the mailbox?
• Who has full access?
• Who can send as the mailbox?
• Who can send on behalf of the mailbox?
• Does each user still need access?
• Are former staff still listed?
• Is the mailbox still needed?
• Does it contain sensitive or customer information?
• Is access limited to the right department or role?

Shared mailboxes that contain finance, HR, customer or confidential information should receive closer attention.

A useful rule is that every shared mailbox should have a named business owner. IT can manage the technical access, but the business owner should decide who needs to remain on the access list.

Review Teams, Microsoft 365 groups and SharePoint access

Collaboration tools make it easy to share information quickly. They can also create access sprawl when Teams, groups and SharePoint sites are created without clear ownership.

A review should identify:

• Teams with no active owner
• Microsoft 365 groups with no clear purpose
• SharePoint sites with excessive permissions
• Users who no longer work with the relevant team
• Guest users who no longer need access
• Old project sites that should be archived or restricted
• Sensitive folders shared too broadly
• Teams or sites that contain customer, finance, HR or confidential data

For each Team or SharePoint site, ask:

• Who owns this workspace?
• What is it used for?
• Who should have access?
• Are external guests still required?
• Is the content sensitive?
• Should access be limited to a smaller group?
• Is the workspace still active?

This does not mean reviewing every Team every month.

For most SMEs, quarterly reviews for collaboration permissions are usually more practical. High-risk or sensitive workspaces may need more frequent attention.

Review external sharing and guest access

External collaboration can be valuable, especially when working with customers, suppliers, contractors or project partners.

However, guest access should not remain open indefinitely.

A practical external access review should check:

• Which guest users are active?
• Which Teams or SharePoint sites can guests access?
• Who approved the guest access?
• Is the business relationship still active?
• Does the guest still need access?
• Are there old supplier or contractor accounts?
• Are external sharing settings appropriate for the type of information stored?

Guest accounts should have an owner inside the organisation.

This owner should be able to confirm why the guest needs access and when that access should be reviewed again.

A simple approach is to review external users quarterly and immediately when a project, contract or supplier relationship ends.

Make role changes a trigger for review

A monthly access review is useful, but some changes should trigger an immediate review.

For example:

• A member of staff leaves
• A staff member changes department
• A manager changes role
• A temporary contractor finishes work
• A supplier contract ends
• A new Team or SharePoint site is created for sensitive work
• An employee is given administrative access
• A security incident occurs
• A user starts handling finance, HR or customer information

These events often create the greatest access risk because permissions may not automatically reflect the person’s new role.

A clear joiner, mover and leaver process is one of the most effective ways to keep access aligned with the organisation.

When a staff member changes role, access should not simply be added to. Old permissions should also be reviewed and removed where no longer needed.

Build a repeatable monthly access review cadence

A checklist only helps when it becomes part of a regular routine.

For SMEs, the process should be lightweight enough to maintain. A simple schedule can provide good governance without creating unnecessary administration.

Monthly quick checks

Review the highest-risk access areas every month:

• Global Administrator and privileged roles
• New admin role assignments
• Disabled or inactive accounts
• Leaver access completion
• New external guest users
• Shared mailbox access changes
• High-risk or sensitive Teams and SharePoint sites
• Outstanding access requests

Quarterly deeper reviews

Review collaboration and business access more thoroughly each quarter:

• Microsoft 365 group memberships
• Team owners and members
• SharePoint site permissions
• Guest access to collaboration spaces
• Shared mailbox access lists
• Supplier and contractor access
• Sensitive data locations
• Old or inactive workspaces

Trigger-based reviews

Carry out a review immediately when:

• Someone leaves or changes role
• A project closes
• A supplier relationship ends
• A new sensitive system is introduced
• A security incident occurs
• A new administrator is assigned
• A business process changes significantly

This approach helps SMEs maintain control without trying to review everything all the time.

The important thing is consistency.

Microsoft 365 access review checklist for SMEs

Use this checklist as a practical starting point.

Identity and user accounts

• All active users have a clear manager or business owner
• Inactive or duplicate accounts are identified
• Leaver accounts are disabled promptly
• User accounts match current job roles
• Shared accounts are removed or tightly controlled
• Multi-factor authentication is enabled for active users
• Privileged users have stronger authentication controls

Administrative roles

• Global Administrator access is limited
• All admin roles have a clear business reason
• Broad admin rights are replaced with lower-privilege roles where possible
• Former staff and suppliers no longer have admin access
• Emergency access accounts are documented and protected
• Administrator access is reviewed monthly

Shared mailboxes

• Every shared mailbox has a named owner
• Full access permissions are reviewed
• Send As and Send on Behalf permissions are reviewed
• Former staff are removed
• Sensitive mailboxes have restricted access
• Unused mailboxes are reviewed for closure or archiving

Teams, groups and SharePoint

• Every Team has at least one active owner
• Old Teams and groups are reviewed
• Sensitive workspaces have appropriate access restrictions
• SharePoint permissions are not overly broad
• Users only have access to workspaces relevant to their role
• Old project workspaces are archived or restricted

External access

• Guest users are reviewed quarterly
• Each guest user has an internal sponsor or owner
• External access is removed when projects or contracts end
• External sharing settings are reviewed
• Sensitive information is not shared more widely than necessary

Governance and reporting

• Access review responsibilities are documented
• Monthly privileged-access checks are completed
• Quarterly collaboration reviews are scheduled
• Trigger-based reviews are part of joiner, mover and leaver processes
• Unresolved access issues have an owner and due date
• Review decisions are recorded

Common access review mistakes

Treating access reviews as an IT-only task

IT can identify permissions and make technical changes, but business owners are usually best placed to confirm whether access is still needed.

Reviewing only user accounts

Access can also exist through groups, Teams, SharePoint sites, shared mailboxes, delegated permissions and external guest accounts.

Leaving old project access in place

Project workspaces often remain active after the work has ended. These should be reviewed, archived or restricted where appropriate.

Giving permanent admin access for convenience

Broad standing access increases risk. Use lower-privilege roles where possible and review elevated access regularly.

Having no ownership for shared mailboxes or Teams

Every important collaboration space should have a clear owner who can approve or remove access.

Making the process too complicated

The best access review process is one that the organisation can actually maintain. Start with high-impact permissions and build the routine over time.

Frequently asked questions

How often should an SME review Microsoft 365 access?

A practical approach is monthly checks for privileged access, quarterly reviews for Teams, groups, shared mailboxes and guest users, plus immediate reviews when staff roles or supplier relationships change.

Who should approve access reviews?

The business owner should approve whether access is still needed. This may be a line manager, mailbox owner, Team owner, site owner, department lead or system owner.

Should all users have the same Microsoft 365 access?

No. Access should match the user’s role and business need. Users should only have access to the systems, files and collaboration spaces needed for their work.

What should we review first?

Start with Global Administrator roles, privileged access, shared mailboxes, sensitive Teams and SharePoint sites, and external guest access.

Do we need advanced Microsoft 365 governance tools?

Not always. Many SMEs can begin with a documented checklist, clear ownership and regular reviews. More advanced automation can be considered as the organisation grows.

Keep Microsoft 365 access under control

Access reviews are one of the simplest ways for SMEs to improve Microsoft 365 governance.

The objective is not to create a complicated approval process. It is to make sure access remains appropriate, owned and aligned with the way people work.

Start with privileged roles and high-impact permissions. Define ownership clearly. Build a monthly and quarterly review routine that the organisation can maintain.

OTUSYN helps growing organisations review Microsoft 365 access, strengthen governance and create practical security controls that support day-to-day work.

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