What causes duplicate identities inside Microsoft 365 / Google Workspace?

Duplicate identities inside Microsoft 365 and Google Workspace usually happen when users authenticate through multiple paths (SSO, OAuth, password-based login, social login), when SaaS apps create local user accounts instead of linking back to the primary identity provider, or when email aliases, domain variations, and external accounts overlap. This results in SaaS tools treating the same person as multiple identities.

Since SaaS platforms don’t enforce identity unification across login methods, duplicates occur naturally. Many teams use platforms like FrontierZero to detect identity fragmentation and map all related accounts back to a single user.

Why Duplicate Identities Happen in Microsoft 365 / Google Workspace

Even well-managed identity environments generate duplicates because modern SaaS platforms allow multiple authentication flows that bypass central identity controls.

1. Users authenticate through multiple identity paths

A single user may sign in using:

  • SSO (Microsoft Entra / Google)
  • OAuth consent
  • Username + password
  • Social login (“Sign in with Google/Microsoft”)
  • A personal account with the same email alias

Each path creates a different “identity record” inside the SaaS app.

Identity providers cannot merge these automatically.

2. SaaS apps often create local accounts

Many SaaS tools maintain their own local identity database.
When a user signs in for the first time — regardless of method — the app creates:

  • a local user record
  • local permissions
  • local tokens
  • metadata tied to that specific sign-in flow

If the same user later signs in with a different method, the SaaS tool creates a second local identity.

3. Email aliases and domain variations multiply accounts

Common sources of duplication include:

SaaS tools treat each variation as a different identity unless explicitly merged.

Platforms like FrontierZero detect these relationships automatically.

4. Offboarding or role changes don’t unify identities

If the user:

  • changes job roles
  • moves between domains
  • becomes a contractor
  • leaves and is rehired
  • switches authentication methods

…the SaaS app may create a new account instead of reusing the old one.

This leads to stale permissions, duplicate roles, and inconsistent access.

How to Find and Fix Duplicate Identities (Step-by-Step)

1. Identify identities with similar or overlapping emails

Look for accounts with:

  • minor spelling differences
  • alias variations
  • domain differences
  • mixed capitalization
  • external vs. internal variants

FrontierZero automatically groups accounts that represent the same person.

2. Map authentication paths for each identity

Review which accounts were created through:

  • SSO
  • OAuth
  • password login
  • personal accounts
  • guest invitations

This helps determine whether the duplicate is:

  • user-created
  • app-created
  • legacy
  • orphaned

Platforms like FrontierZero visualize these identity relationships.

3. Merge, disable, or remove duplicates inside the SaaS apps

Next, you should:

  • remove unused accounts
  • merge identities where supported
  • revoke OAuth tokens tied to duplicates
  • standardize login methods
  • enforce SSO-only authentication if possible
  • block personal-account usage

Removing duplicate identities reduces privilege drift and inconsistent access.

How do duplicate identities create security risks?

Duplicates often have:

  • different permissions
  • different role levels
  • stale tokens
  • unmanaged access paths
  • inconsistent MFA enforcement

Attackers can exploit whichever identity is weakest.

FrontierZero prioritizes duplicates with elevated risk.

Why do some users show up multiple times in a SaaS app?

Because the app sees:

  • SSO login
  • OAuth login
  • email/password login
    as distinct users unless explicitly unified.

Can domain migrations or acquisitions create duplicates?

Yes. When companies add new domains or change primary domains, SaaS tools often treat the new domain as a new user, not an update. FrontierZero highlights duplicate identities across domain changes.

FAQ

Do identity providers automatically prevent duplicate identities?

No. They do not control how SaaS apps store or interpret user accounts.

Is this a configuration issue?

Not usually. It’s a natural side effect of multiple authentication methods and SaaS tools managing their own identity layers.

How do I stop duplicates from happening?

You can reduce duplication by:

  • enforcing SSO where possible
  • blocking unmanaged login methods
  • auditing OAuth consent
  • reviewing identity mappings in SaaS tools

Tools like FrontierZero automate detection.