L 119/118 EN Official Journal of the European Union 4.5.2016 Article 30 Notification of a personal data breach to the supervisory authority 1. Member States shall, in the case of a personal data breach, provide for the controller to notify without undue delay and, where feasible, not later than 72 hours after having become aware of it, the personal data breach to the supervisory authority, unless the personal data breach is unlikely to result in a risk to the rights and freedoms of natural persons. Where the notification to the supervisory authority is not made within 72 hours, it shall be accompanied by reasons for the delay. 2. The processor shall notify the controller without undue delay after becoming aware of a personal data breach. 3. The notification referred to in paragraph 1 shall at least: (a) describe the nature of the personal data breach including, where possible, the categories and approximate number of data subjects concerned and the categories and approximate number of personal data records concerned; (b) communicate the name and contact details of the data protection officer or other contact point where more information can be obtained; (c) describe the likely consequences of the personal data breach; (d) describe the measures taken or proposed to be taken by the controller to address the personal data breach, including, where appropriate, measures to mitigate its possible adverse effects. 4. Where, and in so far as, it is not possible to provide the information at the same time, the information may be provided in phases without undue further delay. 5. Member States shall provide for the controller to document any personal data breaches referred to in paragraph 1, comprising the facts relating to the personal data breach, its effects and the remedial action taken. That documentation shall enable the supervisory authority to verify compliance with this Article. 6. Member States shall, where the personal data breach involves personal data that have been transmitted by or to the controller of another Member State, provide for the information referred to in paragraph 3 to be communicated to the controller of that Member State without undue delay. Article 31 Communication of a personal data breach to the data subject 1. Member States shall, where the personal data breach is likely to result in a high risk to the rights and freedoms of natural persons, provide for the controller to communicate the personal data breach to the data subject without undue delay. 2. The communication to the data subject referred to in paragraph 1 of this Article shall describe in clear and plain language the nature of the personal data breach and shall contain at least the information and measures referred to in points (b), (c) and (d) of Article 30(3). 3. The communication to the data subject referred to in paragraph 1 shall not be required if any of the following conditions are met: (a) the controller has implemented appropriate technological and organisational protection measures, and those measures were applied to the personal data affected by the personal data breach, in particular those that render the personal data unintelligible to any person who is not authorised to access it, such as encryption; (b) the controller has taken subsequent measures which ensure that the high risk to the rights and freedoms of data subjects referred to in paragraph 1 is no longer likely to materialise; (c) it would involve a disproportionate effort. In such a case, there shall instead be a public communication or a similar measure whereby the data subjects are informed in an equally effective manner.