Area Code 55 – Gorica/Koper/Postojna
The phone area code for Gorica/Koper/Postojna is 55 (international format +38655). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 55
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of Gorica/Koper/Postojna
Geographic Coverage and Administrative Jurisdiction
The Slovenian area code 55 is a geographic National Destination Code (NDC) allocated to the western part of the country, encompassing the historic region of Primorska (the Littoral) and parts of the Notranjska region. The code serves the administrative municipalities of Nova Gorica, Koper, and Postojna, along with their surrounding settlements. This area is characterized by its proximity to the Italian border and the Adriatic coast, making it a key economic and tourist hub.
Primary Cities and Local Dialing
The code covers the urban centers of Nova Gorica, a modern city known for its border crossing with Italy; Koper, the country's principal port city; and Postojna, famous for its cave system. When dialing within the same area code, callers can use the abbreviated local format: 5XXXXX (six digits after the trunk prefix). For example, a local call to a subscriber in Nova Gorica would simply require dialing the six-digit number.
International and National Dialing Formats
For callers from outside Slovenia, the full international format is required: +386 55 XXXXXX. From within Slovenia but outside the 55 area, callers must use the national trunk prefix: 0 55 XXXXXX. For instance, a caller from Ljubljana would dial 055 XXXXXX to reach a number in Koper. It is important to note that the leading '0' is only used for domestic calls and is omitted when dialing from abroad.
Overlay and Numbering Plan Considerations
Currently, there is no overlay code for the 55 area; the numbering plan is closed, and all numbers are six digits long after the area code. The Regulatory Authority for Communication Networks and Services of the Republic of Slovenia (AKOS) manages the allocation of these numbers. As with all geographic codes in Slovenia, the 55 code is assigned to fixed-line services, and subscribers may have their numbers ported to VoIP providers, but the geographic significance remains for emergency services and location identification.
Caller Instructions
For local callers: Simply dial the six-digit subscriber number. For national callers: Dial 0 followed by 55 and the six-digit number. For international callers: Dial the international access prefix (e.g., 00 from most countries), then 386, then 55, and the six-digit number. Always omit the leading '0' when calling from abroad. Example: To call a Koper number 123456 from the United States, you would dial 011 386 55 123456.