Area Code 20 – Amsterdam
The phone area code for Amsterdam is 20 (international format +3120). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 20
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of Amsterdam
Geographic Overview
The +31 20 country and area code combination is the international dialing prefix for the Amsterdam numbering area in the Netherlands. This geographic area code serves the capital city and its immediate surrounding municipalities, including Diemen, Duivendrecht, and parts of Amstelveen. As a National Destination Code (NDC) under the ITU-T E.164 standard, 20 is assigned to fixed-line PSTN and VoIP services within this specific geographic region.
Dialing Formats
When calling an Amsterdam number from abroad, the international format is +31 20 XXXX XXXX (or +3120XXXXXXXX without spaces). From within the Netherlands, callers must use the trunk prefix 0 followed by the area code and subscriber number: 020 XXXX XXXX. The local subscriber number is eight digits long, making the total national significant number (NSN) length nine digits (including the leading 0).
Caller Instructions
- International callers: Replace the leading 0 of the national format with +31. For example, to call a number in Amsterdam from the United States, dial 011 31 20 XXXX XXXX.
- Domestic callers: Always include the trunk prefix 0 when dialing from outside the Amsterdam area. Within the same area code, local calls may be dialed using only the eight-digit subscriber number, but this depends on the operator's configuration.
Overlay and Numbering
Amsterdam does not currently have an overlay code; the 20 area code remains exclusive to this region. However, number portability allows subscribers to retain their 20 numbers when switching providers, even if they move outside the geographic area, which can lead to non-geographic usage of these numbers.
Administrative and Economic Significance
As the economic and cultural heart of the Netherlands, Amsterdam hosts numerous corporate headquarters, financial institutions, and government bodies. The 20 area code is therefore associated with a high density of business lines, including major banks, tech companies, and international organizations. The city is also a key European hub for data centers and internet exchange points, making the 20 prefix prominent in the business and technology sectors.
Technical Notes
VoIP providers offering Amsterdam numbers must ensure compliance with the Dutch regulatory framework, including emergency call routing to 112. For callers, it is important to note that while the area code is geographic, the actual physical location of the called party may vary due to number portability. Always verify the current location if the call is for emergency services or location-sensitive purposes.