Home postal code Laos
Laos Postal Code validator
How the postal code format works
- Format
- 5 digits
- Example
- 01000
Things to watch for
- Format-only check — does not confirm the postal code actually exists
- Always exactly 5 digits with no separators, including the leading zero for Vientiane's province code
- The first two digits identify the province and the remaining three the district or town within it
^[0-9]{5}$A Lao postal code is the 5-digit code Enterprise des Postes Lao uses to route mail — for example 01000 for Vientiane. Because Vientiane Capital sits at the front of the province numbering as province 01, every postal code in the capital keeps that leading zero as a required digit rather than a cosmetic one. Anyone validating a Lao shipping address, checkout form, or spreadsheet of customer records needs the leading zero preserved and the full 5 digits present before it’s trusted.
A common data-entry slip is dropping Vientiane’s leading zero when a form or spreadsheet treats the postal code as a number rather than text, silently shortening 01000 to 1000 — a length check catches this immediately.
How this validator works
This tool checks that the input is exactly 5 digits, leading zeros included, with no letters, spaces, or hyphens, entirely in your browser — nothing is sent to a server, and there’s no signup.
What a pass doesn’t tell you
A Lao postal code carries no check digit, so confirming it’s 5 digits long is the most a client-side tool can do — not that it’s been assigned to a real district. Confirming that requires Laos’s own postal code lookup.
Scope: this page and tool cover postal code format validation only — not address lookup, province matching, or confirming a code is currently in use.
postal code FAQ
What do the digits of a Lao postal code encode?
The first two digits identify the province — 01 for Vientiane Capital — and the remaining three narrow it down to a district or town within that province.
Why does Vientiane's postal code start with a zero?
Vientiane Capital is province 01 in Laos's numbering scheme, so its postal codes keep that leading zero as a genuine part of the 5-digit code — dropping it produces a 4-digit string that's the wrong length.
Does a correctly formatted postal code mean it actually exists?
No. This tool only confirms the string is 5 digits — it doesn't check it against Laos's actual postal assignment list. Confirming a code is real requires Lao Postal Enterprise's own lookup.