Area Code 0577 – Siena
The phone area code for Siena is 0577 (international format +390577). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 0577
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of Siena
Overview of Area Code 0577
Area code 0577 is a geographic National Destination Code (NDC) within the Italian national numbering plan, assigned to the province of Siena in the region of Tuscany. It covers the city of Siena and its surrounding municipalities, including but not limited to Poggibonsi, Colle di Val d'Elsa, Monteriggioni, and Chianti areas. The code is used for fixed-line (PSTN) and VoIP services that are registered to a physical address within this area.
Dialing Formats
When calling a number in the Siena area from within Italy, you must dial the trunk prefix 0 followed by the area code and the subscriber number. The complete national format is 0 577 XXX XXX, where the subscriber number typically consists of six to seven digits. For example, a local number might be 0577 123456.
For international callers, the Italian country code +39 is used, and the leading 0 is dropped. Thus, the international format becomes +39 577 XXX XXX. For instance, +39 577 123456.
Local and Overlay Considerations
Within the 0577 area, local calls (i.e., calls to another subscriber within the same area code) can be made using only the subscriber number, without dialing the area code. However, due to number portability and the increasing use of VoIP, it is always safe to dial the full national number (including the 0) to avoid routing errors. As of now, there is no overlay code for Siena; the 0577 code is unique to this geographic area.
Caller Instructions
For local callers: If you are physically within the Siena area and calling another local number, you may dial just the subscriber number. However, if you are calling from a mobile phone or a VoIP line, it is recommended to dial the full number (0577 + subscriber number) to ensure proper routing.
For national callers (outside 0577): Dial 0577 followed by the subscriber number. For example, from Milan, you would dial 0577 123456.
For international callers: Dial your country's international access code (e.g., 00 from most European countries, 011 from the US/Canada), then 39, then 577, and then the subscriber number. For example, from the UK, you would dial 00 39 577 123456.
Administrative and Regulatory Notes
The numbering plan for Italy is regulated by the Autorità per le Garanzie nelle Comunicazioni (AGCOM). Geographic numbers like 0577 are allocated to operators providing fixed-line services. Since the liberalization of telecommunications, subscribers may retain their number when switching providers (number portability). This means that a number with the 0577 prefix may not necessarily be served by the incumbent operator (Telecom Italia), but it will still be associated with the Siena geographic area.