The regulation applies if the data controller (an organisation that collects data from EU residents), or processor (an organisation that processes data on behalf of a data controller like cloud service providers), or the data subject (person) is based in the EU. Under certain circumstances, the regulation also applies to organisations based outside the EU if they collect or process personal data of individuals located inside the EU. The regulation does not apply to the processing of data by a person for a “purely personal or household activity and thus with no connection to a professional or commercial activity.” (Recital 18)

According to the European Commission, “Personal data is information that relates to an identified or identifiable individual. If you cannot directly identify an individual from that information, then you need to consider whether the individual is still identifiable. You should take into account the information you are processing together with all the means reasonably likely to be used by either you or any other person to identify that individual.” The precise definitions of terms such as “personal data”, “processing”, “data subject”, “controller”, and “processor” are stated in Article 4 of the Regulation.

The regulation does not purport to apply to the processing of personal data for national security activities or law enforcement of the EU; however, industry groups concerned about facing a potential conflict of laws have questioned whether Article 48[6] of the GDPR could be invoked to seek to prevent a data controller subject to a third country’s laws from complying with a legal order from that country’s law enforcement, judicial, or national security authorities to disclose to such authorities the personal data of an EU person, regardless of whether the data resides in or out of the EU. Article 48 states that any judgment of a court or tribunal and any decision of an administrative authority of a third country requiring a controller or processor to transfer or disclose personal data may not be recognised or enforceable in any manner unless based on an international agreement, like a mutual legal assistance treaty in force between the requesting third (non-EU) country and the EU or a member state. The data protection reform package also includes a separate Data Protection Directive for the police and criminal justice sector that provides rules on personal data exchanges at national, European, and international levels.

A single set of rules applies to all EU member states. Each member state establishes an independent supervisory authority (SA) to hear and investigate complaints, sanction administrative offences, etc. SAs in each member state co-operate with other SAs, providing mutual assistance and organising joint operations. If a business has multiple establishments in the EU, it must have a single SA as its “lead authority”, based on the location of its “main establishment” where the main processing activities take place. The lead authority thus acts as a “one-stop shop” to supervise all the processing activities of that business throughout the EU (Articles 46–55 of the GDPR).  A European Data Protection Board (EDPB) co-ordinates the SAs. EDPB thus replaces the Article 29 Data Protection Working Party. There are exceptions for data processed in an employment context or in national security that still might be subject to individual country regulations (Articles 2(2)(a) and 88 of the GDPR).