Luxembourg still does not know how many people are living in the country without a residence permit. When questioned by the MP Mars Di Bartolomeo (LSAP), the government states that there is ‘no reliable method’ for counting them. The data from the Directorate-General for Immigration covers only those individuals already known to its services and therefore does not allow for any overall estimate.

Figures from the Labour and Mines Inspectorate, on the other hand, provide a snapshot of irregular employment. Between 2021 and 2025, the ITM carried out 72,155 inspections. Of these, 490 revealed cases of third-country nationals being employed whilst residing in the country illegally or in an irregular situation. In total, 785 workers were identified, 567 fines totalling 4.62 million euros were imposed, and 55 reports were forwarded to the Public Prosecutor’s Office between 2023 and 2025.

The hospitality sector accounts for by far the largest number of cases: 402 out of 785, or 51.2 per cent of the total. Its share rose from 38.5 per cent of those detected in 2021 to 65.1 per cent in 2025. The construction sector comes second with 132 people, or 16.8 per cent, ahead of administrative and support services with 57 cases and retail with 56.

Tougher sanctions

This concentration in the hospitality sector contrasts sharply with the distribution of inspections. Of the 72,155 inspections carried out over five years, 42,094 were in the construction sector, compared with just 2,442 in the accommodation and catering sectors. In 2025, the ITM carried out 8,306 inspections in the construction sector and 526 in the hospitality sector, detecting 9 and 69 undocumented workers respectively.

Penalties have also been significantly increased. The administrative fine, previously set at 2,500 euros per national concerned, has risen to 10,000 euros under the Act of 7 August 2023. The amount of the fines has risen sharply since 2021: €162,500 in 2021, €400,000 in 2022, €1.27 million in 2023 and €1.59 million in 2024, before falling back to €1.195 million in 2025. In total, fines amounting to €4.62 million were imposed over five years.

However, these figures only reflect the detected part of the problem. The ITM highlights, in particular, the absence of written contracts or social security registrations, unpaid wages, excessive working hours, and non-compliant working or housing conditions. And despite the lack of a national estimate, the government states that no scientific study has yet been commissioned to attempt to quantify the number of people residing in Luxembourg without proper documentation.