What posting is
An employer established abroad may temporarily post employees to Luxembourg, to carry out work there for a limited period fixed by a services contract.
The original employment contract continues, and it remains governed by the law of the home country.
But the firm must observe the national rules classed as mandatory by the Luxembourg labour code, covered in the article on the mandatory rules.
That duality characterises posting: a foreign contract, performed under certain Luxembourg rules.
| Obligation | What it requires | Timing |
|---|---|---|
| Posting declaration | Notify the work | Before the works begin |
| Social badge | Carry an individual document | Throughout the work |
| Contact person | Appoint a reachable contact | Before the works begin |
| Documents on site | Keep the papers available | Throughout the work |
The duty to declare
It is clear and its timing is precise.
Any firm not established in Luxembourg posting an employee must inform the administration responsible for labour inspection.
That information must be given at the latest as work begins on Luxembourg territory, without excluding the possibility of declaring earlier.
It is done through a dedicated electronic platform.
It conditions obtaining the social badge for each employee posted, covered in the article on the declaration and social badge.
The key words are "at the latest": the declaration cannot be regularised after work begins without the firm being in default.
The four families of obligations
Posting brings several, often handled separately. The obligations cover the declaration, the documents and the wage.
The declaration itself, with the information required.
Appointing a contact person present on the territory for the duration of the work.
Keeping documents at an address in Luxembourg, with translation where needed.
Observing the mandatory rules on working conditions.
These obligations are cumulative, they do not replace one another, and the last three are covered in the articles of this branch.
The costliest error of reasoning
It consists in believing that exemption from notification means exemption from posting duties. The two regimes are independent of one another.
A firm exempt from notifying its provision of services remains fully subject to the posting obligations.
These two regimes fall to different authorities, pursue different aims and follow different channels.
Notification concerns access to the activity; posting concerns employees and their working conditions.
A European architectural practice, exempt from notification, must therefore declare every employee sent to a Luxembourg site, exactly like a structural works contractor.
This is the point this guide repeats most, because it is the one that exposes most.
What remains governed by home law
Two elements, to distinguish clearly.
The employment contract itself, which continues and remains governed by the law of the home country.
The social security regime, the employee continuing in principle to be covered by the regime of the State where they habitually work, subject to the applicable coordination rules.
That continuity does not dispense with observing the Luxembourg mandatory rules, which apply in parallel.
The articles in this branch
The article on the declaration and social badge covers content and procedure. The procedure is described there.
The article on the contact person covers presence and documentation duties. Their role is set out there.
The article on the mandatory rules covers the applicable law. Their reach is explained there.
This article reflects the rules at the date of checking and serves professional orientation. It does not constitute legal advice.