Area Code 21 – Athens/Piraeus/Salamina

Overview of the 21 Geographic Area Code

In the Greek numbering plan, the prefix 21 is the National Destination Code (NDC) for the greater Athens metropolitan area, encompassing the capital city of Athens, the port city of Piraeus, and the island of Salamina. This geographic area code is assigned to fixed-line PSTN and VoIP services that are physically located within this region. When dialing a number within Greece, the full national significant number (NSN) consists of the NDC followed by a 7-digit subscriber number, resulting in a 10-digit national format: 21x xxxxxxx.

Coverage and Administrative Jurisdiction

The 21 code is subdivided into several specific prefixes that correspond to different zones within the Attica region. For instance, 210 serves central Athens, 211 is an overlay for the entire Attica region, 212 serves the western suburbs, 213 is used for the eastern suburbs, 214 covers Piraeus and the southwestern suburbs, and 215 is assigned to the northern suburbs. These subdivisions allow for more granular routing and are managed by the Hellenic Telecommunications and Post Commission (EETT). The area is the most densely populated in Greece, with a population exceeding 3 million, and hosts the country's primary business, governmental, and cultural institutions.

Dialing Formats and Instructions

When placing a call from within Greece to a number in the 21 area, you must dial the full 10-digit number, including the leading '0' of the NDC. For example, to call a landline in central Athens, you would dial: 210 1234567. If you are calling from outside Greece, you must replace the leading '0' with the Greek country code +30. Thus, the international format becomes: +30 21 1234567 (note that the '0' is omitted). For instance, a caller from the United States would dial: 011 30 21 1234567. It is important to note that the 21 code is not an overlay in the traditional sense; rather, it is a family of NDCs that share the first two digits. However, an overlay does exist: the 211 code was introduced as an overlay for the entire Attica region, allowing for additional subscriber numbers without changing existing numbers. When dialing within an overlay area, 10-digit dialing is mandatory even for local calls.

Caller Instructions

For local callers within the 21 area, you can dial the 10-digit number directly without any trunk prefix, as Greece uses closed dialing plan. For callers from other parts of Greece, the same 10-digit number is used. For international callers, always use the +30 prefix followed by the 10-digit NSN (without the initial '0'). For example, a tourist in Athens wanting to call a hotel in Piraeus would dial 214 9876543, while a business partner in Germany would dial +30 214 9876543.

Number Portability and Modern Considerations

As with all Greek geographic numbers, subscribers may retain their 21 numbers when switching between fixed-line operators, thanks to number portability. Additionally, many businesses and individuals have migrated to VoIP services, but the geographic significance of the 21 code remains important for local presence and trust. It is also worth noting that some mobile numbers may start with 21, but these are not part of the geographic code; they are mobile prefixes (e.g., 21x) that are non-geographic and are assigned to mobile operators. Always verify the type of service before dialing.