What is pseudonymous data?

Pseudonymous data refers to information where personal identifiers have been removed, replaced, or transformed, making it impossible to attribute the data to a specific individual without additional information that is kept separate. 

Unlike anonymous data, which cannot be linked back to an individual at all, pseudonymous data can be re-identified if needed using a secure key stored separately. This process, known as pseudonymization, protects privacy by replacing identifiable details with artificial identifiers such as numbers, codes, or fictitious names, ensuring the main dataset remains secure and compliant with data protection standards.