FakecreditcardHow a Dutch address is written
Dutch addresses are short: street name and house number on one line (Kastanjelaan 27), then postcode and city (3521 KL Utrecht), and the country for international mail. PostNL asks for the postcode and city on the same line with the city in capitals on envelopes, and two spaces between postcode and city are traditional; one space works fine in data. Provinces are never part of the address.
The house number often has an addition (toevoeging) for flats and subdivided buildings: a letter (27A), a number (27-2, meaning the second floor or unit 2), hs (huis, ground floor) or bis. Street names are usually one compound word (Kastanjelaan, Molenstraat, Kerkplein).
Postcode structure
A Dutch postcode is four digits followed by two letters: 3521 KL. The digits identify a city or neighbourhood (the first digit is a broad region, from 1 around Amsterdam to 9 in the north-east); the letters narrow it to a street or one side of a street, often to fewer than 25 addresses. That is why Dutch checkouts ask only for postcode + house number and fill in the street and city automatically.
- The first digit is never
0. - The letter pairs
SA,SDandSSare not used because of their historical associations. - Validation:
^[1-9]\d{3} ?(?!SA|SD|SS)[A-Z]{2}$after upper-casing; users type3521kland3521 KLinterchangeably, so normalise before saving.
Provinces
The Netherlands has 12 provinces (Drenthe, Flevoland, Fryslân, Gelderland, Groningen, Limburg, Noord-Brabant, Noord-Holland, Overijssel, Utrecht, Zeeland, Zuid-Holland). Note the official Frisian spelling Fryslân with a circumflex, and that both Groningen and Utrecht are a city and a province. The Caribbean Netherlands (Bonaire, Sint Eustatius, Saba) have no postcodes at all.
Testing tips for Dutch address forms
- Test a postcode + house-number lookup with generated data: the postcode format is valid but the combination is invented, so the lookup should fail gracefully and allow manual entry.
- Give the house-number addition its own field, or accept
27A,27-2and27 hsin one field. - Sort surnames on the main part: van der Meer belongs under M in Dutch lists.
- Accept the
ijdigraph and diacritics in names (Fryslân,Zoë).
Building a Dutch test data set
Generate addresses across all 12 provinces so the postcodes start with every digit from 1 to 9, and include house-number additions in at least a fifth of the records. Run them through your postcode + house-number lookup: the combinations are invented, so the lookup should return “not found” and your form should still allow the user to type the street and city by hand. Add names with prefixes such as van den Berg to check sorting and capitalisation in the same fixtures.
What makes these addresses fictional
Cities, provinces and the numeric part of each postcode are real; the letters, street names (built from trees, flowers and birds) and house numbers are generated, so any match with a real address is coincidental. Use the data only in test and development systems.
Provinces of Netherlands
The generator uses the 12 first-level provinces below, with the codes used in addresses. Cities are picked from 20 places spread across the country, each with postcodes from its own range.
- DRDrenthe
- FLFlevoland
- FRFryslân
- GEGelderland
- GRGroningen
- LILimburg
- NBNoord-Brabant
- NHNoord-Holland
- OVOverijssel
- UTUtrecht
- ZEZeeland
- ZHZuid-Holland
Example Netherlands test addresses
3521 KL Utrecht
Netherlands
6511 HZ Nijmegen
Netherlands
Validation pattern used for the Postcode: ^[1-9]\d{3} (?!SA|SD|SS)[A-Z]{2}$. It checks the format only — whether a code is actually in use is known only to the postal operator.
Phone numbers in Netherlands test data
Dutch numbers have ten digits starting with 0 (020 for Amsterdam, 06 for mobiles; +31 internationally without the 0). No official fictional range is published that we know of, so the generator leaves the phone blank rather than invent numbers that could belong to someone.
Sources
Postcode ranges, region lists and address conventions checked against these sources in October 2026. Street names in the generator are synthetic.
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Frequently asked questions
What is the Dutch postcode format?
Four digits, a space and two capital letters, for example 3521 KL. The first digit is never 0 and the letter pairs SA, SD and SS are not used.
Why do Dutch forms only ask for postcode and house number?
A postcode covers so few addresses that, together with the house number, it identifies the street and city. Checkouts look up the rest automatically.
Does the generator create Dutch phone numbers?
No. We know of no officially reserved fictional range in the Netherlands, so the phone field stays blank instead of producing numbers that might be in use.
Is this a real address in Netherlands?
No. The city, province and postcode format are real, but the street and house number are random. Use the addresses for testing forms, databases and shipping-rate logic, never to send mail or goods.