The document file every Luxembourg household needs, and when each item is asked for

Luxembourg administration is not heavy, but it is precise, and the same small set of documents is requested repeatedly by different bodies. Building the file once removes most of the friction of the first two years.

The identifiers everything hangs on

Three numbers do most of the work, and it is worth knowing which is which.

Your thirteen-digit national identification number arrives with your social security card once the CCSS has registered your affiliation. It is quoted in every dealing with your health fund and appears across public administration.

Your tax card, the fiche de retenue d'impôt, is issued automatically by the tax administration after the CCSS affiliation, without any application from you, typically within about thirty working days. Where you are taxable in Luxembourg but not affiliated to the CCSS, you have to request it yourself using the appropriate form.

Your commune registration is the entry in the register of natural persons made when you declare your arrival. It is what most other administrations read your address from, which is why keeping it current matters more than it appears.

The housing folder

Keep these together, and keep them for longer than feels necessary.

• The signed lease. Since August 2024 a residential lease must be in writing on pain of nullity, and must state the identity of the parties, the designation of every room and part of the building let, the address and cadastral reference, the rent and charges with the method of calculation, the guarantee, the entry date, and an express mention that either party may refer a rent dispute to the commune's rent commission.
• The entry inventory and its photographs. The single most valuable document you hold, because it is the comparator against which your guarantee is judged at the end.
• Meter readings on the day of entry, with serial numbers and photographs.
• Every charges reconciliation you receive, not just the current one. The trajectory of the advance against the reconciled accounts is what tells you whether an increase is justified.
• Proof of the guarantee payment and any notification of rent revision, which must be sent by registered letter with a month's notice.
• The contents insurance certificate.

Keep the housing folder until the second instalment of your rental guarantee has arrived and the final charges reconciliation is settled, which can be well over a year after you hand back the keys.

The employment and income folder

Employment contract, every payslip, the tax card, and each annual tax assessment. Payslips are requested by landlords, by banks and occasionally by immigration procedures, and the three most recent ones are the standard ask.

Two items worth keeping that people discard: the confirmation of affiliation issued by the CCSS, and any employer letter confirming employment or standing behind a tenancy. Both are difficult to reconstruct and both are exactly what is requested at short notice.

Civil status, and the translation question

Birth certificates, marriage or partnership documents, divorce decrees, and children's documents are requested at the commune, sometimes by the health fund when adding family members, and by schools.

The practical rule is that documents not in French, German or English generally require translation by a sworn translator, and this is applied consistently by communes and by immigration. Getting the translations done once, properly, is considerably cheaper than doing them under time pressure. Order more certified copies than you think you need while you are still in your country of origin, because obtaining them later from abroad is slow.

How to organise it so you can actually find things

Six folders, physical and mirrored digitally: identity and civil status, employment and income, housing, health, vehicle, and correspondence with administrations. Scan everything as a searchable PDF and name files consistently with the date first, so that they sort chronologically.

Two habits that repay themselves. Scan anything you sign at the moment you sign it, before it goes into a bag. And keep a single running note of dates: when you registered at the commune, when the CCSS affiliation was submitted, when the tax card arrived, when the lease started, when the guarantee was paid. Reconstructing that timeline eighteen months later from memory is how disputes become expensive.

What to do when your address changes

Declare the new address at the population office of the new commune within eight days of occupying it. The new commune deregisters you from the old one, so no separate departure declaration is needed.

For someone affiliated to the CCSS, the tax card is updated automatically by the competent RTS office within roughly thirty working days of a change of civil status, private address or employer, with no action required. The exception where your own initiative is needed is a change in the commune where you work without a change of employer.

Then work through the list that does not update itself: bank, insurer, energy supplier, internet provider, employer's HR, and any subscription tied to an address.

Three questions we are asked

How long should I keep tax documents? Longer than you expect. Keep assessments and the payslips supporting them for several years, and keep anything relating to a property transaction indefinitely.

Are digital copies acceptable? For many purposes yes, and MyGuichet handles a growing number of procedures. Originals and sworn translations are still requested for civil status documents, so keep the paper.

What is the one document people wish they had kept? The entry inventory with its photographs. It is produced once, filed casually, and becomes the only evidence that matters when a rental guarantee capped at two months' rent is being returned in two instalments under a statutory procedure.

The health folder, and the receipts people throw away

Luxembourg reimburses rather than bills directly, which means every consultation generates paper you have to act on. Keep the invoices and the proof of payment together until the reimbursement has actually landed, and check it against what you paid rather than assuming.

Four items belong in this folder permanently: the confirmation of affiliation issued after registration, the social security card carrying your thirteen-digit national identification number, any policy documents for complementary cover, and vaccination and medical records brought from your previous country. The last of these is the one people leave behind and cannot easily recover.

Where family members are added to your cover, keep the confirmation of that too, because it is what a hospital or a school will ask to see.

The vehicle folder

If you brought a car, keep the registration documents, the insurance certificate, proof of the technical inspection and any correspondence about registering the vehicle in Luxembourg together. Driving licence questions depend heavily on the country of issue and on your residence status, so verify your own position on guichet.lu rather than relying on what a colleague from a different country tells you.

Two items worth adding: proof of the date you established residence, since several procedures run from it, and the receipt for winter tyres, which is not administratively important but which settles the question of when they were last replaced.

Three questions we are asked

Should I keep paper as well as scans? For civil status documents and sworn translations, yes. Communes and immigration procedures still ask to see originals, and a sworn translation is expensive to reproduce at short notice.

What should I do before leaving my previous country? Order more certified copies of birth, marriage and academic documents than you think you need. Obtaining them later from abroad is slow, and it is invariably needed at the point when speed matters.

Which single habit makes the biggest difference? Scanning anything you sign at the moment you sign it, before it goes into a bag. Almost every document dispute we see involves a paper that was signed, filed casually and then could not be found eighteen months later.