When should organisations review service accounts and API keys?

Why This Matters for Security Teams

Service accounts and api keys are attractive because they rarely trigger user-centric controls, yet they often sit behind the most powerful paths into cloud, CI/CD, and production data. Review cadence matters, but the real risk is drift: access grows, ownership changes, secrets leak into tooling, and dormant credentials remain valid long after the original business need has changed. That is why the best practice is to review on events, not only on a fixed schedule. The NIST Cybersecurity Framework 2.0 emphasises continuous governance and risk-informed control updates, which fits how machine identities actually fail in production.

Recent research from The State of Secrets Sprawl 2026 found that 64% of valid secrets leaked in 2022 are still valid and exploitable today, showing that detection without review and revocation leaves a long tail of exposure. The same pattern appears in incidents documented in 52 NHI Breaches Analysis and the NIST Cybersecurity Framework 2.0, where control failure is usually procedural, not purely technical. In practice, many security teams encounter credential abuse only after a business system or automation pipeline has already been quietly repurposed.

How It Works in Practice

The review trigger should be tied to risk events that change the trust boundary around the credential. Common triggers include employee or vendor offboarding, role or privilege changes, application ownership changes, production incidents, unusual authentication patterns, secret exposure in logs or repositories, and failed or delayed rotation. For service accounts, review the actual workload relationship, not just the name of the account. For api keys, review where the key is stored, who can retrieve it, what it can call, and whether a narrower scope or shorter lifetime is now possible.

Current guidance suggests combining periodic review with event-driven checks. A quarterly or monthly cycle can catch stale accounts, but it is too slow to rely on alone. A change in business process, CI/CD pipeline, or integration partner can instantly make a previously valid secret excessive. NHIMG incident coverage such as BeyondTrust API key breach and Dropbox Sign breach shows how quickly machine credentials can become a lateral-movement path when they are not revisited after environment change.

• Review ownership and business purpose first, then validate whether the credential is still needed.
• Check privilege scope against current job function, system role, and data sensitivity.
• Confirm rotation status, expiry, and whether old versions were fully revoked.
• Inspect telemetry for idle use, anomalous geographies, unusual automation bursts, or access outside expected hours.
• Document the review outcome so future access decisions are based on evidence, not memory.

These controls tend to break down in environments with shared service accounts, long-lived legacy integrations, or undocumented automation because it becomes difficult to prove which process actually depends on the secret.

Common Variations and Edge Cases

Tighter review cycles often increase operational overhead, requiring organisations to balance faster risk detection against the cost of disrupting production integrations. That tradeoff is especially visible in legacy systems, partner APIs, and embedded devices where rotation may require coordinated downtime. There is no universal standard for this yet, so the right review frequency depends on exposure, privilege, and blast radius rather than a one-size-fits-all calendar.

For high-value secrets, current guidance increasingly favours shorter-lived credentials and faster review when ownership changes, even if the account itself is technically still active. This is particularly important where secrets are stored in CI/CD variables, shared vault paths, or agent tooling, because exposure can propagate beyond the original system. The Guide to the Secret Sprawl Challenge and NIST Cybersecurity Framework 2.0 both support the idea that review should be tied to asset criticality and control effectiveness, not compliance theatre. In environments with outsourced operations, M&A, or ephemeral cloud workloads, organisations should add review triggers for contract changes, infrastructure redeployments, and secrets discovered outside source code, because those are the cases where stale credentials most often survive normal governance.

Related resources from NHI Mgmt Group

• How can organisations reduce the risk of stale API keys and machine tokens?
• What problem does ownership attribution solve for service accounts and API keys?
• How should teams reduce the risk of orphaned service accounts and stale tokens?
• How can organisations govern AI agents that use service accounts and tokens?