Identity correlation across siloed accounts is the real IAM gap

At a glance

What this is: This is an analysis of why correlating multiple user accounts to one employee identity is a core IAM control problem, with the key finding that siloed accounts create visibility and governance gaps.

Why it matters: It matters because IAM, IGA, and PAM teams cannot govern joiner-mover-leaver processes, recertification, or access risk accurately when the same person exists as disconnected identities across systems.

By the numbers:

• Only 5.7% of organisations have full visibility into their service accounts.
• NHIs outnumber human identities by 25x to 50x in modern enterprises.
• 80% of identity breaches involved compromised non-human identities such as service accounts and API keys.

👉 Read Axiad's analysis of identity correlation across siloed accounts

Context

Identity correlation is the process of linking separate accounts back to the same real-world person or governed subject. In this article, the primary problem is not authentication failure, but fragmented identity records across cloud, build, and business systems. For IAM programmes, that fragmentation weakens joiner-mover-leaver controls, access reviews, and entitlement decisions because no single record reliably reflects who a user is across the estate.

When employee identity is split across Azure AD, AWS, Jenkins, Artifactory, and HR, every downstream governance process inherits uncertainty. That is a classic identity hygiene problem, and it becomes more serious when teams rely on federation in some places and local accounts in others. The article describes a common enterprise condition, not an edge case: multiple accounts for one person are normal, but correlation logic is often incomplete.

Key questions

Q: How should IAM teams handle employees who have multiple accounts across systems?

A: They should create a canonical identity record that links every account to one governed subject. That record should include HR, directory, cloud, SaaS, and build-system identities so reviews, offboarding, and entitlement analysis are performed once across the whole person, not separately in each system.

Q: Why does account federation not solve identity governance on its own?

A: Federation simplifies sign-in, but it does not eliminate local, legacy, or service accounts, and it does not guarantee that all records point to the same subject. Governance still fails if access reviews and lifecycle actions cannot see the full account set behind one person.

Q: What breaks when identity correlation is missing?

A: Access reviews become fragmented, offboarding becomes incomplete, and entitlement analysis can miss duplicate or excessive access. If separate systems each hold a partial identity view, teams may believe controls are working when the subject is actually governed inconsistently across the estate.

Q: How do organisations know whether identity correlation is working?

A: They should test whether every active account can be linked back to one subject with high confidence and whether exceptions are quickly resolved. Good correlation shows up in cleaner certification results, fewer orphaned accounts, and more complete revocation during offboarding.

Technical breakdown

Identity correlation across siloed accounts

Identity correlation maps separate account records to one governed subject by comparing attributes such as usernames, principal IDs, email addresses, and other stable identifiers. The technical challenge is that no single attribute is universally reliable across platforms, so correlation engines score similarity rather than assuming exact matches. That makes the model probabilistic, especially when people have renamed accounts, different email formats, or partially federated access across environments. In practice, correlation becomes the foundation for accurate entitlement inventory and cross-system access review.

Practical implication: build correlation rules that tolerate attribute drift and do not depend on one identifier as a universal key.

Why federated identity does not eliminate account sprawl

Federation reduces password duplication, but it does not remove the need for local, service, or legacy accounts. Many enterprise systems still issue separate principals for operational reasons, and those principals can diverge from HR or directory records over time. That means federation solves a login problem, not the broader governance problem of identity unification. If a programme treats federated access as proof of identity alignment, it will miss shadow accounts, duplicate records, and offboarding gaps that persist outside the primary directory.

Practical implication: inventory all account types, including local and legacy accounts, before assuming federation has reduced identity risk.

Identity graph building for governance and review

A correlation service effectively creates an identity graph, where nodes are accounts and edges represent evidence that those accounts belong to the same individual. The value is not just technical classification. Once accounts are linked, teams can assess cumulative access, spot contradictory entitlements, and run recertification against the real person rather than against isolated system records. Without that graph, reviews become fragmented and can falsely conclude that no excessive access exists because each system is inspected in isolation.

Practical implication: use a linked identity model as the input to access reviews, role mining, and lifecycle automation.

Breaches seen in the wild

• Azure Key Vault privilege escalation exposure — Azure Key Vault Contributor role misconfiguration enabled privilege escalation.
• Cisco DevHub NHI breach — IntelBroker exploited exposed Cisco credentials, API tokens and keys in DevHub.

Read our 52 NHI Breaches Analysis report for a comprehensive view of breaches impacting Non-Human Identities including AI Agents.

NHI Mgmt Group analysis

Identity correlation is an access-governance control, not a data-quality nicety. The article’s core insight is that IAM collapses when the same employee exists as disconnected principals across cloud and enterprise systems. That creates blind spots in certification, offboarding, and privilege analysis because no control plane can govern what it cannot reliably identify. Practitioners should treat correlation as a prerequisite for enforceable identity governance.

Fragmented identity records create lifecycle debt across the whole programme. A person with separate Azure AD, AWS, Jenkins, and HR records can survive onboarding, transfers, and offboarding as multiple unresolved states. That means revocation may happen in one system while access persists in another, which undermines least privilege and audit readiness. The implication is that identity lifecycle governance must be built around the subject, not the application account.

Unified identity visibility is the named failure mode this article exposes. Axiad’s position points to the operational cost of maintaining multiple account systems without a durable correlation layer. When correlation is weak, entitlement owners cannot tell whether a user already has access somewhere else, and recertification becomes a checkbox exercise instead of a control. Practitioners should read this as a visibility gap with direct governance consequences.

This problem spans human IAM and NHI governance because the same structural issue repeats across actor types. The article is about employees, but the failure pattern is familiar in non-human identity programmes: separate accounts, inconsistent naming, and weak subject linkage. The lesson is that identity governance succeeds when it can establish one accountable subject across systems, whether that subject is a person, service account, or workload. Teams should design for correlation as a cross-domain control.

Correlation quality determines whether identity analytics can be trusted at scale. Once identity data is fragmented, downstream automation only accelerates bad decisions unless the subject model is clean. That is why practitioners need correlation logic before advanced access analytics, not after. The practical conclusion is straightforward: strengthen the subject model first, then automate governance on top of it.

From our research:

• Only 5.7% of organisations have full visibility into their service accounts, according to Ultimate Guide to NHIs.
• 71% of NHIs are not rotated within recommended time frames, increasing the risk of compromise over time.
• 52 NHI Breaches Analysis shows how weak identity visibility and lifecycle control translate into real incidents across the identity stack.

What this signals

Identity correlation will become a programme-level control, not a back-office data task. As identity estates keep splitting across cloud, SaaS, and automation platforms, teams will need one subject view to support reviews, revocation, and assurance. The organisations that treat correlation as governance infrastructure will be better placed to manage both human identity sprawl and the growing non-human estate.

Unified identity graphs create the precondition for useful automation. Without a dependable subject model, access analytics and lifecycle workflows simply automate uncertainty. That is why correlation quality should be measured before teams expand certification, entitlement mining, or offboarding automation.

Account linkage is where IAM, IGA, and NHI governance start to converge. The same design principle applies across human users and machine identities: every principal must resolve to one accountable subject, or control evidence degrades. For practitioners, the next step is to inspect where the identity graph is still stitched together manually and where that creates audit exposure.

For practitioners

• Map every account type to a governed subject record Create a canonical identity record that links HR, directory, cloud, build, and SaaS accounts for each employee. Include local and legacy accounts, not just federated ones, so that access reviews and offboarding operate on the full subject rather than on isolated system entries.
• Treat correlation exceptions as governance defects Route unmatched or low-confidence account links to identity operations for remediation before they enter certification cycles. If an account cannot be tied back to a person with acceptable confidence, it should not be treated as fully governed.
• Rebuild recertification around the subject, not the application Run access review campaigns against the consolidated identity graph so reviewers can see aggregate access across platforms. This prevents multiple partial reviews from hiding excessive privilege or duplicate access patterns.
• Use correlation output to drive offboarding checks When a user leaves or changes role, validate that every linked account has been revoked, disabled, or reassigned. The linked record should be the source of truth for closure evidence across systems.

Key takeaways

• Identity correlation is the hidden control that determines whether access governance can see the real subject behind each account.
• Fragmented account records turn onboarding, review, and offboarding into partial controls that miss excess or lingering access.
• Practitioners should build a canonical identity graph before trusting recertification, analytics, or lifecycle automation.

Key terms

• Identity correlation: Identity correlation is the process of linking multiple account records to one governed subject. It lets IAM and IGA teams understand that separate usernames, principals, or emails may belong to the same employee or workload, which is essential for access review, offboarding, and entitlement analysis.
• Canonical identity record: A canonical identity record is the authoritative subject profile that connects all known accounts for one person or non-human identity. It acts as the reference point for governance decisions so reviews, lifecycle actions, and risk checks are performed against a single trusted view instead of disconnected system records.
• Identity graph: An identity graph is a linked model of accounts, attributes, and relationships that shows how identities relate across systems. In practice, it helps teams see clusters of access, duplicate principals, and unresolved exceptions, which makes governance more accurate than reviewing each platform in isolation.

Deepen your knowledge

Identity correlation and lifecycle governance are core topics in our NHI Foundation Level course, the industry's only accredited NHI security programme. If you are building a governance programme from a similar starting point, it is worth exploring.

This post draws on content published by Axiad: Correlating identities and their users. Read the original.