What should organisations do when access spans multiple systems and business units?

Why This Matters for Security Teams

When access spans multiple systems and business units, the risk is not just over-permissioned accounts. The deeper problem is inconsistent governance: one team approves a service account, another grants a token, and a third maps the same workload to a different entitlement model. That fragmentation makes it hard to see when a single NHI can traverse systems with accumulated privilege. NHI Mgmt Group notes that only 5.7% of organisations have full visibility into their service accounts in the Ultimate Guide to NHIs.

Security teams often assume access reviews will catch this, but reviews usually happen inside one platform and one owner domain. Cross-functional access paths can therefore remain valid long after the business process changes. The OWASP Non-Human Identity Top 10 treats excessive privilege and weak lifecycle control as recurring failure modes because they compound across environments. In practice, many security teams encounter cross-system privilege sprawl only after an incident exposes how many approval paths were never linked together.

How It Works in Practice

Organisations should govern access at the entitlement and process level, not only at the application level. That means defining what a workload, integration or service account is allowed to do, then applying the same policy logic across systems, approval chains and business units. The goal is to make access decisions comparable even when the underlying platforms differ. NIST SP 800-53 Rev. 5 supports this approach through least privilege, separation of duties and access enforcement controls, while the OWASP NHI guidance emphasizes lifecycle visibility and control consistency.

Operationally, this usually means:

• Creating a common entitlement catalog so teams map equivalent privileges across systems.
• Evaluating requests against the same risk threshold, even if one path is manual and another is automated.
• Tracking exceptions centrally so a temporary approval in one unit is visible everywhere else.
• Reviewing access by process ownership, not only by application owner.
• Binding approvals to the business purpose, so drift is easier to detect when the process changes.

This is where the Ultimate Guide to NHIs — Key Challenges and Risks becomes useful: it frames the real issue as visibility and control across the identity lifecycle, not just credential storage. For teams managing shared services or data pipelines, the practical test is whether one policy can answer, “What else can this access now reach?” If the answer changes by system owner, the governance model is too fragmented.

These controls tend to break down when business units maintain separate IAM processes and no common entitlement taxonomy exists, because cross-system comparisons become manual and exceptions quickly disappear into local workflows.

Common Variations and Edge Cases

Tighter cross-system governance often increases approval overhead, requiring organisations to balance consistency against operational speed. That tradeoff is real, especially in federated enterprises, mergers or regulated environments where each unit has its own platform stack and risk tolerance. Current guidance suggests standardising the policy decision, while allowing implementation details to vary by system.

There is no universal standard for this yet, so mature organisations usually adopt a few pragmatic patterns. Shared service accounts may need extra separation of duties. Third-party integrations may require stricter expiry and revalidation rules. Temporary mergers or carve-outs may justify parallel entitlements for a limited period, but those exceptions should be time-bound and reviewable. For broader control design, the OWASP Non-Human Identity Top 10 and NIST controls both support the same principle: access should remain explainable as it crosses boundaries, not become more permissive because ownership changed.

In the most complex environments, the hardest edge case is a workload that inherits access from multiple business processes at once. Those cases need explicit entitlement mapping and exception handling, otherwise a local business decision becomes a hidden enterprise-wide privilege.

Related resources from NHI Mgmt Group

• How should organisations respond when an AI agent inherits access across multiple systems?
• How should security teams prepare for PCI DSS audits when access to cardholder data spans multiple systems?
• Who is accountable when access risk spans multiple business applications?
• Who should own access governance when multiple business systems are involved?