Article 5(1) GDPR states that personal data processing needs to be done lawfully, fairly and in a transparent manner in relation to the data subject.
1. Personal data shall be: (a) processed lawfully, fairly and in a transparent manner in relation to the data subject (‘lawfulness, fairness, transparency’)”
Transparency principle requires open and honest communication towards data subjects about how their personal data is being used. Transparent processing means clear, open and honest communication with individuals about who is processing data, how and why.
It is important to notify individuals about the information you use about them, whether you obtained that information from them directly, or from another source.
The point of transparent processing is enabling individuals to exercise their rights under the GDPR if they wish.
Transparency principle requires data controllers to provide individuals with certain information about the processing of their personal data – fair processing information.