GUIDANCE 1: Controller, Joint Controller, Processor or Secondary Processor?

This guidance is for anyone who wants to understand the different roles played when you are working with others on an activity that involves information about people (personal data).
Read this guidance to understand the different roles played when you are working with others on an activity that involves information about people (personal data). 

Roles, responsibilities, and relationships 
Before you read the guidance it is important to understand that any entity who is working with personal data is likely to be a controller it its own right when it is working with personal data to achieve its own goals. 

However, you need to understand the roles of processors, joint controllers etc. when you start working with other parties to do something with personal data. When this happens, the relationship between yourself and the other parties and the relative roles you play in the specific activity you are working together on need to be defined. 

A key consideration is determining which party is deciding on the purposes and manner of the specific processing, and who is working under instruction.