A system for enabling persons to originate call without using infrastructure in GSM networks which enables a user to originate call to contact numbers registered in GSM, UMTS or fixed-line communication services over a communication network which is a mobile IMS communication network; comprising: - at least one primary electronic device which is a device such as mobile phone, tablet, computer or smart watch configured to enable the user to establish communication over the mobile IMS communication network, whereon at least one SIM card is included, which is configured to ensure that at least one mobile ID number -IMSI-and mobile number -MSISDN- is assigned to the user by the SIM card included on thereof, and which is configured to convey voice data over IP; - at least one secondary electronic device which is a device such as mobile phone, fixed-line phone, tablet, computer or smart watch configured to realize data exchange with the mobile IMS communication network and to ensure that the call originated from the primary electronic device is answered; and characterized by the fact that the system comprises: - at least one application which runs on the primary electronic device, and is configured to: o enable the user to establish communication with the secondary electronic device without using at least one GSM infrastructure, and o enable the user to initiate the registry process by the mobile number -MSISDN- on the SIM card included in his/her primary electronic device; ∘ transmit voice data by secure real time transport protocol and session initiation protocol - SIP-; - at least one registry server which is in communication with the application and is configured to: ∘ ensure that the user is registered to the application by the mobile number that is identified in the SIM card included in the primary electronic device; and o wherein the mobile number is used by means of provisioning services of the mobile IMS communication network; - at least one signalling server which is in communication with the application and is configured to: ∘ ensure that the communication initiated over the application is transmitted to the secondary electronic device over the mobile IMS communication network by using the mobile number; and o ensure that the application is registered in the mobile IMS communication network by using the mobile number. - at least one primary electronic device which is a device such as mobile phone, tablet, computer or smart watch configured to enable the user to establish communication over the mobile IMS communication network, whereon at least one SIM card is included, which is configured to ensure that at least one mobile ID number -IMSI-and mobile number -MSISDN- is assigned to the user by the SIM card included on thereof, and which is configured to convey voice data over IP; - at least one secondary electronic device which is a device such as mobile phone, fixed-line phone, tablet, computer or smart watch configured to realize data exchange with the mobile IMS communication network and to ensure that the call originated from the primary electronic device is answered; - at least one application which runs on the primary electronic device, and is configured to: o enable the user to establish communication with the secondary electronic device without using at least one GSM infrastructure, and o enable the user to initiate the registry process by the mobile number -MSISDN- on the SIM card included in his/her primary electronic device; ∘ transmit voice data by secure real time transport protocol and session initiation protocol - SIP-; o enable the user to establish communication with the secondary electronic device without using at least one GSM infrastructure, and o enable the user to initiate the registry process by the mobile number -MSISDN- on the SIM card included in his/her primary electronic device; ∘ transmit voice data by secure real time transport protocol and session initiation protocol - SIP-; - at least one registry server which is in communication with the application and is configured to: ∘ ensure that the user is registered to the application by the mobile number that is identified in the SIM card included in the primary electronic device; and o wherein the mobile number is used by means of provisioning services of the mobile IMS communication network; ∘ ensure that the user is registered to the application by the mobile number that is identified in the SIM card included in the primary electronic device; and o wherein the mobile number is used by means of provisioning services of the mobile IMS communication network; - at least one signalling server which is in communication with the application and is configured to: ∘ ensure that the communication initiated over the application is transmitted to the secondary electronic device over the mobile IMS communication network by using the mobile number; and o ensure that the application is registered in the mobile IMS communication network by using the mobile number. ∘ ensure that the communication initiated over the application is transmitted to the secondary electronic device over the mobile IMS communication network by using the mobile number; and o ensure that the application is registered in the mobile IMS communication network by using the mobile number.