You will need
- Cell phone, passport.
Today, there are two most simple ways, which allow mobile subscribers to determine the phone numberand their owners who are trying to get "under the guise of" calling number identification restriction number. This service is most common in the home called "Detailing". It is the detail of calls will allow you to get maximum information about the owner of the unknown number.
The detail of calls through a call to the helpdesk of your mobile operator. Just note that such a possibility is far not each operator (check with support). Contact the Manager, ask for call detail records (if any) for the desired period. Your account will be charged the cost of service. After a while the number will come SMS message with a detailed report about incoming calls.
If your carrier does not provide the procedure for remote authorization, you can make a similar request to its nearest office. After you confirm the fact that you are the owner of this roomand you will be provided a detail of calls for a specific period of time. To determine the unknown room, look in the phone the date of the last call and find the same date you provided the documents. Phone number, date of call which will coincide with a call of "incognito" is the most anonymous.