Manual reviews become too risky when the organisation has multiple systems, frequent role changes, or large volumes of human and non-human access. At that point, spreadsheet-based tracking creates delays, routing errors, and incomplete remediation, which undermines least privilege and auditability.
Why This Matters for Security Teams
Manual access reviews stop being safe the moment they can no longer keep pace with the identity surface. That threshold arrives faster than many teams expect because NHI inventories are larger, more dynamic, and more failure-prone than human IAM. NHIs outnumber human identities by 25x to 50x in modern enterprises, and only 5.7% of organisations have full visibility into their service accounts, according to the Ultimate Guide to NHIs. When reviewers are chasing spreadsheets, the delay itself becomes a security control failure.
The risk is not just missed findings. Manual recertification often leaves stale entitlements in place long enough for lateral movement, privilege creep, and audit gaps to accumulate. That matters even more when access spans cloud workloads, CI/CD systems, and secrets stores that should already be governed with NIST Cybersecurity Framework 2.0 practices and identity-aware controls. The practical tipping point is when review volume, exception handling, and remediation latency exceed what one team can close before the next role or system change lands. In practice, many security teams discover this only after a stale account or mis-scoped service principal has already been used, rather than through intentional review design.
How It Works in Practice
A manual review process becomes too risky when it cannot reliably answer four questions at scale: who owns the access, what business purpose it serves, whether the permission is still needed, and how quickly it can be removed if it is not. For human access, that usually means RBAC mapping, manager attestations, and exception routing. For NHI access, the same pattern is weaker because the entitlement is often tied to code, pipelines, tokens, certificates, or runtime dependencies rather than a stable job title. The Ultimate Guide to NHIs — Key Challenges and Risks describes why visibility and lifecycle control are central to the problem, not just periodic certification.
A safer operating model usually combines automated discovery, policy-based scoring, and workflow-driven approvals. Security teams should segment reviews by risk tier, so high-impact privileges get faster treatment and low-risk access can be grouped for exception-free recertification. Where possible, review evidence should be pulled from authoritative sources rather than email threads or spreadsheets. Current guidance suggests aligning this with OWASP Non-Human Identity Top 10 risk categories, then using NHI Lifecycle Management Guide patterns to tie each entitlement to provisioning, rotation, and revocation events.
A practical review flow often includes:
- inventory reconciliation against IAM, cloud, and secrets systems
- owner validation for each account or token
- risk scoring based on privilege level, last use, and environment
- automatic removal of clearly orphaned or over-privileged access
- escalation only for exceptions that need human judgment
This guidance tends to break down in legacy environments where account ownership is undocumented and revocation depends on manual coordination across multiple admin consoles.
Common Variations and Edge Cases
Tighter access review controls often increase operational overhead, requiring organisations to balance assurance against review fatigue and business disruption. That tradeoff is especially visible in environments with contractors, shared admin roles, or machine identities embedded in build systems. In those cases, a pure manual attestation model can produce false confidence because approvers may not understand the technical dependency behind the access, while a fully automated model may remove permissions that a critical workload still needs.
Best practice is evolving for mixed human and non-human estates. Some teams run separate review lanes for human users, service accounts, and API keys because the evidence required for each category differs. For NHI-heavy environments, the review should emphasise standing privilege, token lifetime, secret storage location, and rotation status rather than org chart ownership alone. The Ultimate Guide to NHIs notes that weak visibility and delayed remediation are persistent issues, which is why manual review should be reserved for edge cases, not the default operating model. External validation from OWASP Non-Human Identity Top 10 and NIST Cybersecurity Framework 2.0 supports the shift toward continuous, evidence-based governance.
The hard edge case is regulated or safety-critical systems where revocation windows are constrained by uptime or formal change control. In those environments, manual review can still play a role, but only as a policy checkpoint layered on top of continuous discovery and automated enforcement, not as the primary control.
