How an address is written in Luxembourg

The order the lines go in

The parts are named rather than filled in: Spaw does not know an address in Luxembourg and will not invent one. This block is produced by the same function that rewrites a real address, so the line order, the capitals Luxembourg asks for and any text its operator prints on every envelope are the checker's own behaviour rather than a second description of it.

Organisation
12 Street name
Flat or unit
L-Postal code Town or city

No recipient line: nothing in the response is about a person, so the name the envelope carries is not part of what is checked.

In Luxembourg the house number comes before the street name, and that is the side it is written back on when the checker rewrites an address. The postal code is written before the town.

Can Spaw tell whether an address in Luxembourg exists?

Yes. The BD-Adresses of Luxembourg's Administration du cadastre et de la topographie lists 358,848 addresses in Luxembourg (version 31 October 2026). It is declared a complete address register, so an address it holds answers exists: true and one it does not answers exists: false. A false has two honest failure cases: a building added after the version in use, and an address spelled so differently from the register that no variant of its street matches. That is why a miss is scored rather than refused.

A postcode directory answers a different question. The postal code is confirmed separately by GeoNames' postal code list, which does not list every code, so one it does not hold is not flagged.

Further reading: How to read an address-existence answer and How an open register locates a building.

Check an address in Luxembourg

The same lookup the API runs, with Luxembourg already selected.

The postal code

Postal codes in Luxembourg are four digits. Its operator prints the prefix L- in front of the digits; a code written with it is accepted, and so is one written without.

pattern \d{4}

What Luxembourg calls an address that is not a front door

A PO box, a private mailbox and the other kinds of delivery point below are told apart by the words written on the address, never by a list of whose box is whose. The rows marked as the operator's own words are taken from the addressing guide of the postal operator in Luxembourg; the others are international spellings, not the operator's own. All of them are what the checker reads, and because an entry is carried for Luxembourg, an address here with none of them answers street.

The anchored spellings are the conservative half of this: those words are ordinary language elsewhere in an address, so they only count when they open the line and carry a number after them.

What can be checked for an address in Luxembourg

Read from the datasets this server holds right now, not written into the page. For most countries the answer is the written form and the postcode shape and nothing beyond them — in particular not the row people assume is always there.

Null means not evaluated, never no.

Other countries

• Cayman Islands
• Lebanon
• Liechtenstein
• Lithuania
• Latvia
• Monaco
• Moldova
• St. Martin
• Check any address
• Every dataset behind the checker

Sources

• Google's Address Data Service · address-formats 2026-09-05© Google LLC, CC BY 4.0 (Google Address Data Service); initial import via commerceguys/addressing (MIT)
• The postal operators' addressing guides · address-rules 2026-09-17
• The BD-Adresses of Luxembourg's Administration du cadastre et de la topographie · lu-bd-adresses 2026-10-31BD-Adresses, Administration du cadastre et de la topographie (Luxembourg), CC0
• GeoNames' postal code list · geonames-postal-codes 2026-10-31Postal codes, places and centroids from GeoNames (geonames.org), CC BY 4.0.

Data synced on 2026-10-31: the newest version among the datasets listed above.