Home code postal Luxembourg
Luxembourg Code Postal validator
How the code postal format works
- Format
- 4 digits
- Example
- 1009
Things to watch for
- Format-only check — does not confirm the code postal actually exists
- Always exactly 4 digits; the L- prefix seen on addresses (e.g. L-1009) marks the country, not part of the code this validator checks
- The leading digit is a rough regional marker — 1 and 2 both fall within Luxembourg City itself
^[0-9]{4}$A Luxembourg postal code is the 4-digit code POST Luxembourg uses to route mail — for example 1009, conventionally written with the country prefix as L-1009. Because the entire country is small enough that Luxembourg City alone accounts for two full leading-digit blocks (1xxx and 2xxx), the leading digit works more like a loose zone marker than the region-per-digit scheme larger countries use, with remaining digits (3 through 9) fanning out to the south, east, north, and west of the capital. Anyone validating a Luxembourg shipping address, a checkout form, or a spreadsheet of customer records needs the postal code in the correct 4-digit shape before it’s trusted.
Because it’s a bare run of digits with no separator, a transposed digit produces a code that still looks entirely plausible.
How this validator works
This tool checks that the input is exactly 4 digits with no letters, spaces, or hyphens — the L- country prefix sometimes shown on international mail is not part of the code this validator checks — entirely in your browser, with nothing sent to a server.
What a pass doesn’t tell you
A Luxembourg postal code carries no check digit, so matching the 4-digit shape is the most a client-side tool can confirm — not that POST Luxembourg has assigned it to a real street. Confirming that requires POST Luxembourg’s own postcode lookup.
Scope: this page and tool cover format validation only — not address lookup or confirming a postal code is currently in use.
code postal FAQ
Why does Luxembourg City itself span more than one postcode prefix?
Because Luxembourg is a small country covered almost entirely by one metropolitan area, both the 1xxx and 2xxx blocks fall within Luxembourg City itself, rather than the leading digit marking a distinct region the way it does in larger countries.
What does the L- prefix mean on a Luxembourg address?
It's the ISO country prefix used for international mail, e.g. L-1009. This validator checks only the 4 numeric digits — the L- prefix marks the country, not part of the postal code itself.
Does a correctly formatted postal code mean it actually exists?
No. This tool only confirms the string is 4 digits — it doesn't check it against POST Luxembourg's actual assignment list. Confirming a postal code is real, and seeing which street it covers, requires POST Luxembourg's own postcode lookup.