Third-party AI governance: the SS2/21 lens, applied to vendors and models.

Almost no organisation trains its own foundation model — AI risk is very often a vendor's model, not yours. This hub assembles everything on the site tagged with the third-party lens: the risks, controls, and terminology that apply whenever governance, compliance, security, or engineering responsibility depends on a party you don't control.

Last reviewed: 2026-07-29

Four pillars, one dependency.

Third-party AI risk isn't a fifth concern alongside the pillars — it's each of the four, applied to a system you don't fully control.

Governance

Who owns the vendor relationship, who signs off on onboarding a new AI model or platform, and whether that accountability survives the vendor changing its own terms.

Compliance

Obligations that flow through to you regardless of who runs the model — data protection, the EU AI Act, and sector rules don't stop at the API boundary.

Security

A third-party model or platform's attack surface becomes yours the moment you integrate it — provenance and supply-chain assurance, not just uptime SLAs.

Engineering

Whether the AI you depend on is mapped into your important-business-service inventory, with a tested impact tolerance for when the vendor fails.

What AI-specific due diligence checks.

Extending the SS2/21 discipline most firms already run for material outsourcing, not replacing it.

  • Model and dataset provenance: where the training data came from, and whether the vendor can actually answer that question.
  • Sub-outsourcing visibility: what the vendor itself outsources, and whether you have visibility into that chain, not just the vendor you signed a contract with.
  • Concentration and exit: what happens if this vendor becomes unavailable, and whether an exit plan exists before you need one.
  • Contractual assurance: audit rights, incident-notification obligations, and data-handling terms specific to AI, not a generic outsourcing template.

Everything tagged with this lens.

Pulled live from the library — assembled by the third-party facet, not a hand-maintained list.

1 glossary term

Frequently asked questions

Why does third-party AI governance need its own hub instead of being one topic under Governance?

Because it genuinely cuts across all four pillars — governance of the vendor relationship, compliance obligations that flow through the vendor, security of a third-party model or platform, and the operational-resilience discipline of knowing what happens if the vendor fails. A single-pillar page would force an artificial split.

What is SS2/21 and why does it matter for AI vendors?

The Bank of England PRA's supervisory statement on outsourcing and third-party risk management. It already tells firms what due diligence looks like for material outsourcing, including cloud and new technology — AI vendor risk is that same discipline applied to AI specifically, not a new framework.

What should AI vendor due diligence check that generic vendor due diligence might miss?

Model and dataset provenance, sub-outsourcing visibility (what the vendor itself outsources), concentration risk and exit planning, and contractual terms — audit rights and incident notification — written for an AI system specifically, not adapted from a generic outsourcing template.

This is one of the areas Andrew advises on.

Third-Party & Operational Resilience Risk is one of five areas of expertise on the services page, grounded in exactly this SS2/21 discipline.