How should large public-sector organisations approach identity modernisation across multiple programmes and services?

Large public-sector organisations should treat identity modernisation as a governed programme, not a one-time tool rollout. The work needs a clear target operating model, phased migration, and alignment with existing business services so access decisions stay consistent. Strong identity governance, stakeholder ownership, and careful change management matter because different programmes often have different legacy constraints and risk profiles.

Why This Matters for Security Teams

Identity modernisation across public-sector portfolios is not just a platform upgrade. It is a control-plane change that affects citizen-facing services, internal administration, third-party access, and auditability at the same time. When organisations run multiple programmes with different legacy directories, approval chains, and service owners, inconsistent identity policy becomes a delivery risk as well as a security risk. Guidance such as NIST SP 800-53 Rev 5 Security and Privacy Controls is useful, but it still needs local governance to stay consistent across programmes.

NHI Management Group research shows the scale of the problem is often underestimated: only 5.7% of organisations have full visibility into their service accounts, and 80% of identity breaches involved compromised non-human identities such as service accounts and API keys. That matters in public-sector environments where one weakly governed service account can cross organisational boundaries and undermine trust in multiple services. The practical challenge is not choosing an identity product, but aligning identity decisions with business ownership, security classification, and operational support across an entire estate. In practice, many teams discover identity drift only after a shared service or legacy integration has already expanded access beyond what the original programme intended.

How It Works in Practice

A workable modernisation approach starts by treating identity as a common service with clear operating rules, rather than as a series of isolated migrations. Programmes should agree on shared patterns for authentication, authorisation, privileged access, and lifecycle management, while allowing exceptions where legacy constraints genuinely require them. The target state should define how human identities, service accounts, API keys, and other secrets are issued, reviewed, rotated, and retired. The Ultimate Guide to NHIs is a useful reference for the lifecycle and governance issues that often get missed when teams focus only on login modernisation.

Practitioners usually get the best results by sequencing the work:

• Establish a portfolio-wide identity governance model with named service owners and decision rights.
• Inventory identities and dependencies before changing platforms, including service accounts, machine credentials, and shared admin paths.
• Standardise policy where possible, using common controls for MFA, least privilege, privileged access management, and secrets handling.
• Use phased migration so high-risk services and low-risk services do not follow the same cutover path.
• Monitor for exceptions, because exceptions often become the permanent architecture if they are not time-boxed.

For control design, public-sector organisations should map modernisation activities to established control families such as access control, configuration management, and audit logging in NIST SP 800-53 Rev 5 Security and Privacy Controls. For the risk-driven side of the programme, the Top 10 NHI Issues research is a strong reminder that secrets sprawl, poor rotation, and incomplete offboarding can persist even after a new IAM platform is introduced. These controls tend to break down when multiple shared services depend on hard-coded credentials and no single programme owner can enforce retirement deadlines.

Common Variations and Edge Cases

Tighter identity standardisation often increases delivery overhead, requiring organisations to balance security consistency against programme autonomy and legacy compatibility. That tradeoff is most visible in federated public-sector environments, where agencies, delivery partners, and inherited systems may use different protocols or have different statutory constraints. Best practice is evolving, but current guidance suggests avoiding a forced big-bang migration when service continuity and audit obligations are high.

One common edge case is where a central identity team owns the platform but local programmes own the service integration. That model can work if governance is explicit, but it breaks down quickly when no one is accountable for stale entitlements, service-account sprawl, or emergency access. Another edge case is a shared citizen platform that must support both modern apps and older batch processes. In those environments, the modern target state may need a bridge period with compensating controls, not an immediate decommission.

Public-sector modernisation also needs a realistic view of reporting. Leadership often wants one standard operating model, but operational evidence usually arrives in fragments from multiple systems. That is where the 52 NHI Breaches Analysis is especially relevant: identity failure is usually cumulative, not single-point, and the weakest programme becomes the easiest route into the rest of the estate. The right answer is not perfect uniformity on day one, but governed convergence with measured exceptions and a clear retirement path for legacy controls.

Related resources from NHI Mgmt Group

• How should public sector organisations evaluate identity security controls for cloud services under GovRAMP or similar frameworks?
• How should public sector organisations evaluate identity security platforms for sensitive government workloads?
• How should large organisations centralize identity management across cloud and on-premise applications?
• What breaks when organisations manage identity separately across multiple business units and platforms?