Area Code 33 – Amersfoort
The phone area code for Amersfoort is 33 (international format +3133). Browse local exchange codes (NXX) and carrier assignments below.
📞 Exchange Codes (NXX) for Area Code 33
Select a central office code to view local carrier data and detailed information
📍 Geographic Location of Amersfoort
Overview of Area Code +31 33
Area code +31 33 is a geographic National Destination Code (NDC) assigned to the city of Amersfoort and its surrounding municipalities in the province of Utrecht, Netherlands. This code is part of the Dutch numbering plan administered by the Authority for Consumers and Markets (ACM) and follows the ITU-T E.164 standard. The geographic area covered by +31 33 includes Amersfoort, Leusden, Nijkerk, Bunschoten, and smaller towns such as Hoogland and Achterveld.
Dialing Formats
When calling a landline in Amersfoort from within the Netherlands, you must use the trunk prefix 0 followed by the area code and the subscriber number. The national format is 033-XXXXXXX, where the subscriber number consists of seven digits. For international callers, the country code +31 is used, and the leading zero is dropped: +31 33 XXXXXXX.
Example: A local number in Amersfoort might be 033-1234567. From abroad, you would dial +31 33 1234567.
Geographic Coverage and Administration
The +31 33 area code serves the northern part of the province of Utrecht, with Amersfoort as the principal city. Amersfoort is one of the largest cities in the Netherlands and a major transport hub. The code is also used in the adjacent municipalities of Leusden and Nijkerk (which lies in Gelderland province but is included in the Amersfoort numbering area). This allocation is based on historical telephony boundaries and remains unchanged despite municipal reorganizations.
Numbering and Overlay Considerations
Currently, there is no overlay code for the Amersfoort area; the 033 code is the sole geographic area code for this region. Subscriber numbers are seven digits long, and the total number of possible combinations is sufficient for the region's demand. However, as with all Dutch geographic codes, number portability allows subscribers to retain their numbers when moving to a different provider, but the geographic significance remains tied to the original location.
Caller Instructions
- Local callers (within the Netherlands): Dial 033-XXXXXXX (including the trunk prefix 0).
- International callers: Dial your country's exit code, then 31 33 XXXXXXX (omit the leading 0).
- Callers from mobile phones in the Netherlands: Dial the full national number 033-XXXXXXX; the network will route the call to the fixed line.
For businesses and residents in the Amersfoort area, using the +31 33 code is essential for establishing a local presence. When dialing from abroad, always replace the leading zero with the +31 country code to ensure proper international routing.