subprocessors

A subprocessor is a third party engaged by a data processor to process personal data on behalf of a data controller. Subprocessors perform specific processing activities under contract, and may handle data such as storage, analytics, or support tasks as part of the service. The data controller remains accountable for complying with data protection laws, while the processor coordinates the use of subprocessors to fulfill processing purposes.

Under many data protection regimes, notably the GDPR, processors may engage subprocessors only under a written contract that imposes data protection obligations equivalent to those in the processing agreement with the controller. The controller typically must be informed about subprocessors, may object to certain subprocessors, and must grant or withhold general authorization. Subprocessors are bound by flow-down obligations to protect the data and to follow the controller's instructions.

Key obligations include implementing appropriate security measures, assisting with data subject rights, and notifying the processor of a data breach. The processor remains liable to the controller for the acts or omissions of subprocessors as if they were its own. In many jurisdictions, data processing agreements or standard contractual clauses govern these arrangements, and may require audit rights or evidence of compliance.

Risk management and governance are important: maintain an up-to-date roster of subprocessors, define clear purposes, ensure data minimization, establish termination rights and data return or deletion at contract end, and maintain clear liability and remedies in case of non-compliance.

In practice, subprocessors are common in cloud services, IT outsourcing, and software as a service, where providers rely on a network of subcontractors for storage, computation, or specialized processing tasks.