Area Code 258 – Denizli

Overview of Area Code 258 (Denizli, Türkiye)

Area code 258 is a geographic National Destination Code (NDC) assigned to the province of Denizli in southwestern Türkiye, under the country calling code +90. This code covers the administrative province of Denizli, including its central municipality and all connected districts. The numbering plan follows the ITU-T E.164 standard, with a total national significant number (NSN) length of 10 digits for all calls within Türkiye.

Geographic Coverage and Administrative Jurisdiction

The 258 area code serves the entire Denizli Province, which is part of the Aegean Region. The primary city is Denizli, a major industrial and commercial hub known for textile manufacturing and tourism (e.g., Pamukkale). Other important districts under this code include Merkezefendi, Pamukkale, Acıpayam, Çivril, Sarayköy, and Buldan. The code is administered by the Information and Communication Technologies Authority (BTK) of Türkiye, which oversees all numbering resources.

Dialing Formats and Caller Instructions

For callers within Türkiye, the national dialing format is 0 258 XXX XX XX, where the leading 0 is the trunk prefix used to access the national network. For international callers, the format is +90 258 XXX XX XX (or 00 90 258 XXX XX XX from most countries). The subscriber number is 7 digits long, and the total number of digits after the trunk prefix (or country code) is 10. For example, a local Denizli number might be 0 258 261 45 67; from abroad, dial +90 258 261 45 67.

When calling from a mobile phone within Türkiye, it is essential to include the trunk prefix 0 even for local calls, as the Turkish numbering plan requires it for all calls to geographic numbers. For callers outside Türkiye, replace the trunk prefix with the international access code (e.g., 00) and then the country code 90, followed by the area code without the leading zero.

Overlay and Numbering Considerations

As of the latest BTK updates, there is no overlay code for Denizli; the 258 code is the sole geographic code for the province. However, number portability is in effect, meaning that subscribers may retain their 258 numbers even if they move to a different operator, but the geographic significance remains tied to the original assignment. All landline numbers under 258 are fixed-line services, typically provided by Türk Telekom and alternative operators. Mobile numbers in Denizli are assigned separate non-geographic codes (e.g., 5xx series) and are not part of the 258 area code.

For businesses and residents, it is important to note that calls to 258 numbers from mobile networks are charged according to the caller's tariff, but they are considered national calls. There are no special premium or toll-free services associated with this code; it is strictly for PSTN and VoIP fixed-line services.