Privacy and personal data

Silent calls, when you answer the phone and there's no one on the other end, can cause concern, but they are not usually malicious.

Generally these calls are made by automatic systems that make a large number of outgoing calls from a call centre at once. This system is used by companies trying to contact customers to sell and market products or services or for market research.

The calls are processed automatically by the call centres and as soon as a call is answered by a customer, the automatic system transfers it to a call centre agent. However sometime all of the call centre agents are busy with other calls and your call is not attended; this means that when you answer there is nobody on the other end.

These calls may cause concern and annoyance, especially if they are frequent.

If you do not wish to receive such calls, you should contact your telephone service provider. Your provider must provide you with an option that lets you easily block incoming calls whose number are withheld. However, you should be aware that this option blocks all calls with unidentified numbers and not just those that originate from the specific unidentified number in question.

You can also ask your provider to annul the confidentiality of the number. The provider will analyze your request and, if it is consistent with the principles of necessity, proportionality and appropriateness, it may void the confidentiality of the number of the person calling you, for a period not exceeding 30 days. However, as this measure concerns personal data, a mandatory opinion of the CNPD - Comissão Nacional de Proteção de Dados (National Commission for Data Protection) is required before it can be implemented.

Where technically feasible, the companies providing telephone services are required to ensure that the subscriber making a call has the option, using simple means, to prevent their number being identifiable to the person who receives the call.

You should therefore contact your service provider, who will provide you with clear and current information about this option.

As the current operator of the universal service, PT Comunicações is required to prepare, publish and make available, on an annual basis, a telephone directory with details of all subscribers to telephone services, including the customers of other operators. PT Comunicações is also required to make the same data available through a directory enquiry service (available by calling 118). This is the number that you can call whenever you need information about a particular phone number.