What breaks is the ability to remove access cleanly. Organisations may retire a subscription while leaving behind admin roles, API keys, synced identities, or shadow accounts in the duplicate system. Without identity review, the old app can remain a live access path even after the business stops using it.
Why This Matters for Security Teams
SaaS rationalisation often looks like a clean-up exercise, but if identity review is skipped, the result is usually residual access rather than real retirement. A subscription can be removed from procurement records while service accounts, OAuth grants, API keys, and synced identities continue to authenticate in the background. That is why identity and application inventories have to be reconciled together, not treated as separate projects.
NHI Management Group’s Ultimate Guide to NHIs notes that only 20% of organisations have formal processes for offboarding and revoking API keys, and even fewer rotate them consistently. That gap matters because retiring an app does not automatically invalidate the non-human identities attached to it. The same pattern shows up in breach write-ups like the Salesloft OAuth token breach, where credentialed access outlived normal expectations. Current guidance from the NIST Cybersecurity Framework 2.0 supports continuous asset and identity management, which is exactly what app rationalisation needs.
In practice, many security teams discover the problem only after an old SaaS tenant is still accepting logins, API calls, or synced account changes long after the business has stopped paying for it.
How It Works in Practice
The failure mode is usually a mismatch between software lifecycle management and identity lifecycle management. Application owners decide a SaaS tool is redundant, but identity teams are never asked to review what is bound to it. That leaves behind the operational plumbing: admin roles, delegated tokens, SCIM-linked users, service principals, webhook secrets, and machine-to-machine credentials. The business sees a decommissioned app; the attacker sees a still-valid authentication path.
Effective rationalisation needs a joint cutover checklist. First, inventory the app, all connected identities, and every trust relationship. Second, classify each identity as human, service account, integration token, or synced account. Third, validate whether the app is the source of truth for any downstream access. Fourth, revoke access in an order that prevents orphaned entitlements. Fifth, confirm deletion or disablement at both the SaaS layer and the identity provider.
- Use identity review to identify who or what can still authenticate before subscription termination.
- Check OAuth grants, SCIM syncs, API keys, and admin roles separately, since each fails differently.
- Require evidence of revocation, not just a procurement closure ticket.
- Reconcile inactive apps against the service account inventory and secrets register.
This is also where the identity governance model matters. NHI Management Group’s Top 10 NHI Issues highlights that excessive privilege and poor visibility are common across machine identities, and that reality does not improve just because an app is marked for retirement. Identity-oriented control mapping in NIST CSF 2.0 and related access governance practices helps teams prove that access was actually removed, not assumed removed. These controls tend to break down when SaaS tenants are shared across business units and one team decommissions an app while another still relies on its integration credentials.
Common Variations and Edge Cases
Tighter rationalisation often increases coordination overhead, requiring organisations to balance faster application reduction against the risk of breaking legitimate integrations. That tradeoff is especially visible in multi-tenant SaaS, where one subscription supports several business functions, or when an app is only partially retired and continues to serve as an identity bridge to another platform.
Best practice is evolving, but current guidance suggests treating identity dependencies as a mandatory part of every application retirement review. That includes human users, guest accounts, machine identities, and any inherited trust from SSO or directory sync. If a legacy app was used to create downstream accounts, those accounts may also need separate review and revocation. If the app issued tokens or certificates, those secrets should be rotated or invalidated before decommissioning, not after.
Some teams assume the SaaS vendor will remove everything automatically. In reality, vendor disablement can stop the interface but still leave side effects in directories, automation scripts, caches, and connected apps. The 52 NHI Breaches Analysis shows a recurring pattern: abandoned credentials and overlooked machine access become durable entry points. In short, the harder the environment relies on synchronisation and automation, the more identity review has to lead rationalisation.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Non-Human Identity Top 10 and CSA MAESTRO address the attack and risk surface, while NIST CSF 2.0 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-03 | Covers lifecycle and offboarding of non-human identities tied to retired SaaS apps. |
| NIST CSF 2.0 | PR.AA-01 | Identity management must track who and what can still authenticate after rationalisation. |
| CSA MAESTRO | IAM-03 | Agentic and machine access governance depends on removing dormant trust paths in SaaS. |
Verify every app retirement includes revoking machine identities, tokens, and API keys before closure.
Related resources from NHI Mgmt Group
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on June 11, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
