A parallel run happens when both organisations keep their identity systems operating during an integration. This creates a temporary state with no single source of truth for identity and entitlement data. It is common in M&A and requires explicit authority, precedence, and reconciliation rules to prevent access confusion and duplicate records.
Expanded Definition
identity provider Parallel Run is a temporary operating model in which two identity systems remain active during a merger, migration, or platform transition. In NHI and IAM practice, the term matters because authentication and entitlement decisions may be issued by both systems at once, creating a short-lived split in authority.
Industry usage is still evolving, but the operational requirement is clear: define which system is authoritative for a given identity class, which system can provision or revoke access, and how conflicts are resolved when records diverge. That makes this concept closely related to governance, reconciliation, and decommissioning, not just login continuity. It also intersects with Zero Trust assumptions described in the NIST Cybersecurity Framework 2.0, where access decisions must remain consistent even during architectural change.
Parallel run is often confused with simple coexistence, but coexistence becomes risky when duplicate identities, inconsistent group membership, or delayed revocation create competing truths. The most common misapplication is treating both providers as equally authoritative, which occurs when migration teams omit precedence rules for overlapping accounts and entitlements.
Examples and Use Cases
Implementing Identity Provider Parallel Run rigorously often introduces reconciliation overhead, requiring organisations to weigh migration safety against temporary duplication and operational complexity.
- A company moving from one workforce IdP to another keeps both live while users are migrated in waves, with one system designated as source of truth for each department.
- During an acquisition, the buyer and target company maintain separate directories while access to SaaS tools is mapped and merged, using explicit precedence rules for conflicting roles.
- An engineering org runs parallel identity platforms for a limited period so service accounts and machine identities can be validated before cutover, reducing outages for automation workloads.
- A governance team uses parallel run reports to compare group membership, privileged assignments, and disabled accounts, then resolves drift before final decommissioning.
- Lessons from the 52 NHI Breaches Analysis show how identity overlap can mask stale access, while NIST Cybersecurity Framework 2.0 reinforces the need for controlled transitions and asset governance.
Parallel runs are also common when migrating developer and CI/CD access, where token-based workflows cannot tolerate abrupt identity cutover. They are especially useful when revocation logic, federation settings, or application-specific RBAC mappings need validation across both systems before one is retired.
Why It Matters in NHI Security
Parallel runs matter because they can quietly expand the attack surface if duplicate accounts, stale API keys, or conflicting privilege assignments persist across both identity systems. In NHI environments, that risk is amplified because machine identities often outnumber human identities and are harder to inventory during transition. NHIMG research shows that only 5.7% of organisations have full visibility into their service accounts, and that visibility gap becomes even more dangerous when two identity providers are operating side by side. The Ultimate Guide to NHIs also notes that 97% of NHIs carry excessive privileges, which means duplicate authority during a parallel run can compound existing over-permissioning.
Governance teams need clear reconciliation logic for joins, leaves, role changes, credential rotation, and emergency revocation. Without that, the parallel state becomes a hiding place for orphaned entitlements and inconsistent offboarding. The operational lesson aligns with the Top 10 NHI Issues, where unmanaged identity sprawl repeatedly appears as a root cause of access failure and breach exposure. Organisations typically encounter the consequences only after an access dispute, privilege escalation, or failed deprovisioning event, at which point Identity Provider Parallel Run becomes operationally unavoidable to address.
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, NIST Zero Trust (SP 800-207) and NIST SP 800-63 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-01 | Parallel runs create duplicate identities and authority conflicts that NHI governance must control. |
| NIST CSF 2.0 | PR.AC-1 | Identity proofing and access control must stay consistent while two providers coexist. |
| NIST Zero Trust (SP 800-207) | SC-7 | Zero Trust requires controlled access decisions even when identity sources are in flux. |
| NIST SP 800-63 | IAL2 | Identity assurance breaks down if two providers issue inconsistent or unverified identity records. |
| CSA MAESTRO | IA-2 | Agentic and machine identities need consistent authority when platforms overlap during migration. |
Define authoritative source, reconciliation, and decommission steps before running two identity systems in parallel.
Related resources from NHI Mgmt Group
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on August 24, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
