When a third party’s model is involved, who answers for the outcome?
Enhanced: 22 controls
Who it applies to
Enter for every AI system whose letter is E or A (this area has no Baseline controls). Go as deep as your system letter, and implement in your mode.
Why it exists
Settle, in advance and in writing, who is answerable for what when a decision runs through a third party’s model — because responsibility that is not fixed will be disputed at exactly the moment it matters. You cannot delegate accountability to your provider (the Governance principle), but you can and must allocate the specific responsibilities across the chain: which failures are yours, which are the provider’s, and how that is evidenced. Do it in the contract, before the incident, not in the argument after it.
What to actually do
Allocate the specific responsibilities in the contract. Using the Sourcing dimension’s contractual layer, state which failures and harms fall to the provider and which to you, and how each is evidenced. “The vendor’s model did it” is not a defence; “our contract makes the vendor responsible for this specific failure, and here is the record” is a position.
Keep the accountability with you where the law keeps it with you. For many outcomes — especially decisions about people — the accountability to the affected individual and the regulator remains yours regardless of contract. Recognise this explicitly, so you do not build a governance model that assumes a transfer the law does not permit.
Controls
Enhanced2 controls
Control 186
Allocate supply-chain responsibilities contractually, per failure type.
EnhancedPreventiveall rolesper system
What it is
Who answers for what, and how it is evidenced.
How to implement it · Minimum structure
Failure types: harmful or wrong output, data leak, unannounced model change, outage, security breach
For each failure type: who answers for it (provider, organisation, other party) and what each must do
Evidence: logs, version records and incident reports the provider must supply, and within what time
Notice: provider informs the organisation of incidents and model changes within an agreed period
Remedies per failure type: correction, service credits, indemnity or termination
How to start
Take the current contract for this system and map each failure type to the clause that covers it; the gaps become the negotiation list.
Evidence
The signed contract or annex with the responsibility allocation per failure type.
Mode: light / standard / full
light
Where terms are not negotiable, note which failures the standard terms leave with the organisation.
standard
A negotiated responsibility annex for each material provider, reviewed by legal counsel.
full
A standard responsibility schedule applied by procurement and legal to every AI provider, tracked in the contract register.
Control 187
Record where accountability remains with you regardless of provider.
EnhancedPreventiveall rolesper system
What it is
So the governance model reflects the law, not a wished-for transfer.
How to implement it · Minimum content
System and use case concerned
Accountability retained: decisions about people, answers owed to affected individuals, duties towards the regulator, obligations over the personal data
Reason it cannot be transferred: the legal rule or contractual limit
Internal owner who answers for each retained accountability
How the governance model covers it: oversight position, decision records, redress route
How to start
For this system, list who its decisions affect and which obligations towards them stay with the organisation whatever the contract says; confirm the list with legal advice.
Evidence
The retained-accountability record, signed by its owner and linked to the contractual allocation.
Mode: light / standard / full
light
A short section in the system's file, written once with an external lawyer or adviser.
standard
A register kept per system by the legal or compliance lead.
full
Part of the governance model, reviewed by legal at each change of provider or of the applicable rules.
Evidence
The contractual responsibility allocation; the record of retained accountabilities; evidence used to attribute a specific failure across the chain.