The basic prerequisites for immigration to Luxembourg depend on **why the person is moving** there, but for most **non-EU / third-country nationals**, the main requirements are usually these:

**1. A valid reason for immigration**
The applicant must have a clear legal purpose to stay in Luxembourg, such as:

* work,
* study,
* family reunification,
* business or self-employment,
* private reasons,
* research, internship, or seasonal work. ([Guichet.lu][1])

**2. A valid passport**
A valid passport is one of the standard requirements for both entry and long-stay procedures. Official Luxembourg guidance lists this clearly for students and other third-country nationals. ([Guichet.lu][1])

**3. Temporary authorisation to stay before travel**
For many long-stay immigration cases of **more than 90 days**, the person must first apply for a **temporary authorisation to stay** from the General Department of Immigration **before entering Luxembourg**. This is a key step for categories like students, workers, researchers, and private-reason residence. ([Guichet.lu][1])

**4. A type D visa, when required**
After getting the temporary authorisation to stay, applicants who are from countries that need a visa must then apply for a **long-stay visa (type D)** before entering Luxembourg. ([Guichet.lu][1])

**5. Supporting documents for the purpose of stay**
The person must prove the purpose of immigration with documents, for example:

* work contract or employer documents for workers,
* school admission or enrolment for students,
* family relationship documents for family reunification,
* business documents for self-employed applicants. ([Guichet.lu][2])

**6. Sufficient financial means and suitable accommodation**
Applicants often need to show that they can support themselves financially. In family reunification cases, Luxembourg also requires proof of **sufficient resources** and **appropriate housing** for the sponsor and family members. ([Guichet.lu][3])

**7. Arrival and residence formalities after entry**
After arriving in Luxembourg, many long-stay applicants must:

* make a **declaration of arrival** at the commune,
* undergo a **medical check** where required,
* apply for a **residence permit** within the legal deadline. ([Guichet.lu][2])

A clean, simple answer for your travel agency would be:

**The basic requirements for immigration to Luxembourg usually include a valid passport, a clear reason for stay such as work, study or family reunification, the required supporting documents, proof of financial means, and in many cases a temporary authorisation to stay and a type D visa before travel. After arrival, applicants may also need to declare their arrival, complete a medical check, and apply for a residence permit.** ([Guichet.lu][2])

I can also turn this into a **very short FAQ answer** or a **professional website version** for your agency.

[1]: https://guichet.public.lu/en/citoyens/immigration/plus-3-mois/ressortissant-tiers/etudiant/etudiant-pays-tiers.html?utm_source=chatgpt.com "Conditions for residence in Luxembourg for students from third ..."
[2]: https://guichet.public.lu/en/citoyens/immigration/plus-3-mois/ressortissant-tiers/membre-famille/regroupement-familial.html?utm_source=chatgpt.com "Application for family reunification for third-country nationals"
[3]: https://guichet.public.lu/dam-assets/catalogue-formulaires/immigration/document/tiers/regroupement-familial/autorisation-sejour-note-regroupement-familial/regroupement-familial-tiers-note-en.pdf?utm_source=chatgpt.com "Authorisation to stay for a family member of a third-country ..."