There are public call boxes almost everywhere, and most of them accept international telephone cards. One unit for a call from Cuba to Germany costs about 5 CUC.
There are also public telephones in most hotels, and hotel guests can usually make outward calls directly from their rooms.
International calls from Cuba: dial 119, then the country and area codes and finally the phone number.
International calls to Cuba: the country code for Cuba is 0053. Here is a list of regional area codes:

• Pinar del Río (province capital): 82
• Valle de Viñales: 8
• Havanna: 7
• Matanzas (province capital):: 45
• Varadero: 45
• Playa Girón und Playa Larga: 45
• Santa Clara (province capital): 42
• Remedios: 42
• Caibarién: 42
• Cienfuegos(province capital): 432
• Cayo Largo del Sur: 45
• Sancti Spíritus (province capital): 41
• Trinidad: 419
• Topes de Collantes: 42
• Ancón: 419
• Ciego de Ávila (province capital): 33
• Cayo Coco: 33
• Morón: 335
• Camagüey (province capital): 32
• Playa Santa Lucía: 32
• Florida: 32
• Playa Covarrubias: 31
• Las Tunas (province capital): 31
• Holguín (entire province): 24
• Granma (entire province):: 23
• Santiago de Cuba (province capital: 22
• Baracoa: 21

Mobile telephony/cellphones

Both TDMA and GSM mobile networks are used on Cuba, however they do not cover all regions. In built-up areas, such as Havana and Varadero, you are certain to find an available network, but you should check with your provider before leaving if and where you will be able to use your phone in Cuba.
Otherwise you can rent a phone from the Cuban provider Cubacel.

Internet and Fax

Almost all hotels provide internet access or at least the ability to send and receive email. The cost is around 6 US$ per hour. The appearance of internet pages can take considerably longer than you are used to because the connection is made via satellite.

Virtually all hotels in Cuba provide national and international fax reception and transmission for guests and non-guests alike.