Data protection, location and international transfers
Access control systems process personal data (identifiers, access events, sometimes biometrics). Under the UK GDPR, you must document lawful basis, minimisation, retention and security controls—and if you’re using a cloud provider that stores or accesses data outside the UK, you also need a valid international transfer mechanism. The ICO’s guidance on international transfers explains when a transfer is “restricted” and sets out mechanisms such as adequacy decisions, the UK’s International Data Transfer Agreement (IDTA) and Binding Corporate Rules (BCRs). Build these considerations into supplier due diligence and contracts; ensure you know where data is stored and who can access it.
If you plan to use biometrics for identification, treat templates and event logs with heightened care (they will often be special category data). Cloud vs on-prem doesn’t remove those duties; it simply changes who is doing what under the controller/processor relationship. The ICO’s general guidance on cloud use and privacy hygiene is a helpful primer for non-specialists you need to brief internally.
Availability, resilience and operations
A credible on-premises system can be highly available, but you must engineer it: clustered servers or failover VMs, routine backups, tested restores, UPS and generator coverage, and clear patching windows. Cloud-managed platforms typically offer built-in resilience across multiple data centres and frequent updates without customer downtime; your focus shifts to tenant configuration, strong admin authentication and the security of any gateways or API integrations you operate. The NCSC’s cloud guidance emphasises secure administration and protection of management interfaces—a frequent weak point if not actively managed.
At the door, design for independence. Controllers should cache permissions and continue to enforce policy during temporary loss of connectivity, then reconcile events later. This is as important for cloud platforms as it is for on-prem servers over a congested WAN.
Cost and lifecycle
With on-premises, you’ll typically capitalise servers, storage and licences upfront and carry operational costs for patching, backups and eventual refresh. Cloud shifts you toward a subscription model with predictable operating expense; you eliminate most server care-and-feeding but introduce ongoing licence consumption. Neither is inherently cheaper—it depends on scale, staffing and how aggressively you maintain security hygiene (which you should, in both cases).
A useful way to compare is a five-to-seven-year total cost of ownership: software/licence uplift, server hardware or cloud subscriptions, support, integrations, and the often-overlooked time your teams spend on patching, upgrades and audits.
Integration and enterprise architecture
Most estates need access control to work with CCTV and intruder alarms so events drive context and response. Both on-prem and cloud systems can integrate well if you choose platforms with proven APIs and event hooks, and plan integration from day one. We outline pragmatic patterns—like using an access event to bring up the corresponding camera—in our guide to CCTV–Access Control–Alarm Integration. (See: CCTV–Access Control–Alarm Integration)
From an IT perspective, consider how the system fits your identity and access management strategy (for example, single sign-on and strong MFA for administrators). The NCSC’s identity guidance and Cloud Security Principles provide clear, vendor-neutral benchmarks that will make your platform review and internal sign-off easier.
When cloud makes more sense
Cloud-managed access control tends to win for multi-site estates, organisations with lean IT teams, and programmes that want rapid feature updates and simple, secure remote administration. It’s also attractive if your broader strategy is cloud-first and you already operate robust identity, MFA and conditional access policies across SaaS services, in line with NCSC guidance.
Do your homework on data location, transfer mechanisms and the provider’s operational security. Ask for audit logs you control, tenancy-level encryption options, and a clear statement of how the platform aligns to the NCSC’s principles.
