Data Controller vs. Data Processor Requirements Under GDPR

GDPR distinguishes between:

• Data Controllers: Organizations that determine the purposes and means of processing personal data

• Data Processors: Organizations that process personal data on behalf of a controller

Controllers must:

• Demonstrate a lawful basis for processing

• Manage and respond to data subject rights requests

• Conduct DPIAs where required

• Ensure processors provide sufficient guarantees of GDPR compliance

Processors must:

• Process data only on documented instructions from the controller

• Implement appropriate security measures

• Assist controllers in fulfilling GDPR obligations

• Maintain a Record of Processing Activities (RoPA)

• Notify the controller of any data breaches without undue delay

Clear contracts (Data Processing Agreements) are essential to establish responsibilities and manage risk—also aligning with ISO 27001 and SOC 2 best practices.