Iceland póstnúmer validator
How the póstnúmer format works
- Format
- 3 digits
- Example
- 101
Things to watch for
- Format-only check — does not confirm the póstnúmer actually exists
- Always exactly 3 digits — the shortest postcode in this comparison, reflecting Iceland's small population
- 101 Reykjavík (the city centre) is well known enough to be used as a cultural shorthand for the district itself
^[0-9]{3}$An Icelandic póstnúmer is the 3-digit postcode used to route mail, written directly before the town name — for example 101 Reykjavík for the capital’s city centre. Because Iceland’s population is small relative to most countries in this comparison, 3 digits is enough to give every town and district a unique code without running out of room, unlike the 5- or 6-digit systems larger neighbours need.
That brevity cuts both ways: with only 3 digits and no separator, a single mistyped or transposed digit lands squarely on a different, equally plausible-looking póstnúmer rather than producing an obviously malformed string.
How this validator works
This tool checks that the input is exactly 3 digits with no letters, spaces, or hyphens, entirely in your browser, with nothing sent to a server.
What a pass doesn’t tell you
A póstnúmer carries no check digit, so matching the 3-digit shape is the most a client-side tool can confirm — not that Íslandspóstur has assigned it to a real town or district. Confirming that requires Iceland’s own postcode lookup.
Scope: this page and tool cover format validation only — not address lookup or confirming a póstnúmer is currently in use.
póstnúmer FAQ
Why is the Icelandic póstnúmer so short compared to other countries?
At just 3 digits, it's one of the shortest postcodes anywhere — a direct consequence of Iceland's small population, which needs far fewer distinct delivery areas than a large country covered by a 5- or 6-digit grid.
What does '101 Reykjavík' mean?
101 is the póstnúmer for Reykjavík's city centre, and the phrase has become cultural shorthand for that downtown district specifically — it's even the title of a well-known Icelandic film. Most Icelanders instantly recognise 101 as 'downtown Reykjavík' rather than just a routing code.
Does a correctly formatted póstnúmer mean it actually exists?
No. This tool only confirms the string is 3 digits — it doesn't check it against Íslandspóstur's actual assignment list. Confirming a póstnúmer is real, and seeing which town or district it names, requires Iceland's own postcode lookup.