What remains to be done once started
Three categories of obligation continue.
Tax obligations, notably as regards value added tax, covered in the article on VAT registration.
Duties of documentary availability, covered in the article on site inspections.
Duties of updating, every change having to be reported.
These three categories fall to different authorities, and a firm in order on one may be in default on another.
| Ongoing obligation | What it requires | Frequency |
|---|---|---|
| Updating declarations | Report any change | At each change |
| Documents available | Keep the papers on site | At all times |
| Tracking the applicable regime | Recheck if the works run on | Periodically |
The principle of updating
This is the thread running through the ongoing obligations. They are checked throughout the duration of the works.
Declarations made before starting describe a given situation.
That situation changes: contact person, place where documents are kept, accommodation of employees, composition of teams, duration of the mission.
Every change must be reported through the same channel as the initial declaration, as the article on the declaration and social badge explains.
A declaration accurate at the start but since become false no longer protects.
On a long project this point produces the most unintentional non-compliance.
What must stay available at all times
Four items, at any point during the work. They must be producible at an inspection.
The social badges of each posted employee present.
The documents kept at the address declared in Luxembourg.
The translations, where the originals are not in French or German.
Evidence of permit or notification, according to the applicable regime.
Availability is a substantive requirement, not a formality: a document that exists but is inaccessible is equivalent to a missing one at an inspection.
Monitoring the applicable regime
A review to plan for, not merely a performance. The position is rechecked if the project runs on.
The duration of the work may tip the regime, as the article on when work becomes establishment explains.
Widening the services may fall outside the scope of the permit, as the article on the professions concerned recalls.
Using a subcontractor mid-project creates new obligations, covered in the article on subcontracting.
These three developments are common on a project, and none triggers an automatic alert.
The articles in this branch
The article on VAT registration covers tax. The thresholds are set out there.
The article on site inspections covers checks. How they proceed is described there.
The article on penalties covers the consequences of default. The regimes are set out there.
The article on developments to watch covers what is moving. The reforms are followed there.
This article reflects the rules at the date of checking and serves professional orientation. It constitutes neither tax nor legal advice.