Are Phone Numbers Protected Under GDPR?
Posted: Tue May 27, 2025 9:23 am
The General Data Protection Regulation (GDPR) is a comprehensive privacy law enacted by the European Union (EU) to protect personal data and privacy of individuals within the EU and the European Economic Area (EEA). Since phone numbers are often linked to individuals, a key question is whether phone numbers are considered personal data under GDPR and how they are protected.
1. Are Phone Numbers Personal Data?
Under GDPR, personal data is defined as “any information relating to an identified or identifiable natural person.” This means data that can directly or indirectly identify a person.
Phone numbers, especially mobile phone numbers, are generally considered personal data because they can be linked to an individual.
Even a landline number can be personal data if it can identify a specific household or person.
Numbers assigned to businesses may not be personal data unless they can be traced back to an individual.
Thus, phone numbers are usually treated as personal data under GDPR.
2. Implications of Phone Numbers as Personal Data
Because phone numbers are personal data, their collection, processing, storage, and sharing are subject to GDPR rules:
Lawful Basis for Processing: Organizations must have a lawful reason to process phone numbers, such as consent, contractual necessity, legal obligation, or legitimate interest.
Consent: If consent is the basis, it must be freely given, specific, informed, and unambiguous. For example, businesses must clearly explain how the phone number will be used and get explicit permission.
Purpose Limitation: Phone numbers must be collected recent mobile phone number data for specified, explicit, and legitimate purposes and not used in ways incompatible with those purposes.
Data Minimization: Only collect phone numbers that are necessary for the intended purpose.
Accuracy: Ensure phone numbers are accurate and up-to-date.
Storage Limitation: Retain phone numbers only as long as needed.
Security: Implement appropriate technical and organizational measures to protect phone numbers against unauthorized access or breaches.
3. Special Cases
Marketing and Telephony: Phone numbers used for marketing calls or SMS must comply not only with GDPR but also with additional regulations such as the EU ePrivacy Directive and national telemarketing laws.
Data Subject Rights: Individuals have rights regarding their phone numbers, including:
Right to access the data held about them
Right to rectification (correct inaccurate numbers)
Right to erasure (have their number deleted under certain conditions)
Right to object to processing, especially for direct marketing
4. Risks of Non-Compliance
Mismanaging phone numbers can lead to:
Data breaches exposing phone numbers and associated personal data
Fines from regulatory authorities (GDPR fines can reach up to 20 million euros or 4% of annual global turnover)
Reputational damage and loss of customer trust
5. Best Practices for Handling Phone Numbers under GDPR
Always obtain clear consent before using phone numbers for marketing.
Use secure systems for storing and transmitting phone numbers.
Regularly audit data processing activities involving phone numbers.
Provide transparent privacy notices explaining how phone numbers are handled.
Enable easy mechanisms for users to update or delete their phone numbers.
Conclusion
Phone numbers are considered personal data under GDPR because they can identify individuals. As such, they are protected by GDPR’s strict rules on data processing, consent, security, and individual rights. Businesses must handle phone numbers carefully, ensuring compliance to avoid legal and reputational risks.
1. Are Phone Numbers Personal Data?
Under GDPR, personal data is defined as “any information relating to an identified or identifiable natural person.” This means data that can directly or indirectly identify a person.
Phone numbers, especially mobile phone numbers, are generally considered personal data because they can be linked to an individual.
Even a landline number can be personal data if it can identify a specific household or person.
Numbers assigned to businesses may not be personal data unless they can be traced back to an individual.
Thus, phone numbers are usually treated as personal data under GDPR.
2. Implications of Phone Numbers as Personal Data
Because phone numbers are personal data, their collection, processing, storage, and sharing are subject to GDPR rules:
Lawful Basis for Processing: Organizations must have a lawful reason to process phone numbers, such as consent, contractual necessity, legal obligation, or legitimate interest.
Consent: If consent is the basis, it must be freely given, specific, informed, and unambiguous. For example, businesses must clearly explain how the phone number will be used and get explicit permission.
Purpose Limitation: Phone numbers must be collected recent mobile phone number data for specified, explicit, and legitimate purposes and not used in ways incompatible with those purposes.
Data Minimization: Only collect phone numbers that are necessary for the intended purpose.
Accuracy: Ensure phone numbers are accurate and up-to-date.
Storage Limitation: Retain phone numbers only as long as needed.
Security: Implement appropriate technical and organizational measures to protect phone numbers against unauthorized access or breaches.
3. Special Cases
Marketing and Telephony: Phone numbers used for marketing calls or SMS must comply not only with GDPR but also with additional regulations such as the EU ePrivacy Directive and national telemarketing laws.
Data Subject Rights: Individuals have rights regarding their phone numbers, including:
Right to access the data held about them
Right to rectification (correct inaccurate numbers)
Right to erasure (have their number deleted under certain conditions)
Right to object to processing, especially for direct marketing
4. Risks of Non-Compliance
Mismanaging phone numbers can lead to:
Data breaches exposing phone numbers and associated personal data
Fines from regulatory authorities (GDPR fines can reach up to 20 million euros or 4% of annual global turnover)
Reputational damage and loss of customer trust
5. Best Practices for Handling Phone Numbers under GDPR
Always obtain clear consent before using phone numbers for marketing.
Use secure systems for storing and transmitting phone numbers.
Regularly audit data processing activities involving phone numbers.
Provide transparent privacy notices explaining how phone numbers are handled.
Enable easy mechanisms for users to update or delete their phone numbers.
Conclusion
Phone numbers are considered personal data under GDPR because they can identify individuals. As such, they are protected by GDPR’s strict rules on data processing, consent, security, and individual rights. Businesses must handle phone numbers carefully, ensuring compliance to avoid legal and reputational risks.