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Europe · +31

Netherlands phone number format

  • Country code +31
  • Trunk prefix 0

Reviewed by Sujan ThapaliyaLast updated

What does a Netherlands phone number look like?

9 digits after the trunk 0. Landlines are written +31 XX XXX XXXX and mobiles +31 6 XXXX XXXX. In full international (E.164) format a Netherlands mobile is written +31612345678: the country code +31, with the national trunk prefix 0 removed, and no spaces or punctuation.
The anatomy of a Netherlands phone number under ITU-T E.164: country calling code 31, then the national destination code, then the subscriber number, to a maximum of fifteen digits after the plus. Nationally a Netherlands number is written +31 XX XXX XXXX with the trunk prefix 0; in E.164 the prefix and the spacing both come off.
National formatting is for people. E.164 is for databases, APIs, and caller ID — store Netherlands numbers in the right-hand form.

Format rules

Country code
+31
National number length
9 digits after the trunk 0
Trunk prefix
0
Used only domestically. Removed in international format.
Landline pattern
+31 XX XXX XXXX
Mobile pattern
+31 6 XXXX XXXX

Examples

Netherlands phone number examples

These are format patterns showing digit grouping and prefix rules. They are examples of shape, not working numbers; do not use them to test a live call path.

TypeWritten domesticallyInternational (E.164)
Landline020 123 4567+31201234567
Mobile06 XXXX XXXX+31612345678

A quirk of Netherlands numbering

Every Dutch mobile number starts 06 domestically, which becomes +31 6 internationally.

Validation

How to validate a Netherlands number

Validating a phone number is three separate checks, and conflating them is the usual source of bugs:

  1. Format: does it match the shape for Netherlands? 9 digits after the trunk 0, after the country code and with the 0 stripped.
  2. Allocation: is the prefix actually in use? A number can be the right length and still belong to an unallocated range.
  3. Reachability: is there a live subscriber? Only a carrier lookup (HLR or equivalent) answers that, and it is the only check that catches disconnected numbers.

For form validation, check format only and be permissive: accept spaces, dashes, brackets, and a leading 0 then normalise. Rejecting a real customer because they typed their own number the way they normally write it is a far more expensive error than storing one badly formatted row.

Store in E.164 (+31612345678) and format for display at render time. Storing the display format is how a database ends up with the same person recorded four different ways.

Format any number instantly

Paste a number into the free phone number formatter to convert it to E.164 and see whether it matches Netherlands’s format rules. No sign-up.

Frequently asked questions

What does a Netherlands phone number look like?
9 digits after the trunk 0. A landline is written +31 XX XXX XXXX and a mobile +31 6 XXXX XXXX. In full international format that becomes +31612345678.
How do I write a Netherlands number in international format?
Start with +31, remove the leading 0 from the national number, then append the rest with no spaces or punctuation. +31 20 123 4567 becomes +31201234567.
How many digits is a Netherlands phone number?
9 digits after the trunk 0.
How do I tell a Netherlands mobile from a landline?
By the prefix. Mobiles follow the pattern +31 6 XXXX XXXX, while landlines follow +31 XX XXX XXXX.
Should I store phone numbers with the plus sign?
Yes. Store every number in E.164: leading +, country code, national number, no spaces or punctuation, up to 15 digits. It is the only format that is unambiguous internationally, and it is what makes deduplication work. Format for display, store canonical.

Sources

  1. ITU-T Recommendation E.164 — The international public telecommunication numbering plan — International Telecommunication UnionThe international number format, the 15-digit maximum, and how country codes and national numbers compose.
  2. ITU-T International Numbering Resources — International Telecommunication UnionThe assignment of country calling codes and the published national numbering plans they belong to.

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