Personal taxation · Luxembourg
Luxembourg tax office and tax number: where to find them
The right contact depends on the procedure: the tax office for Form 100, the RTS office for the tax withholding card or the annual tax adjustment, the collection office for allocating payments. Use the references shown on the official letter for your file.
Financial Services Luxembourg · Licensed accountant · Head of the firm: Mickaël LOC. Editorial update: .
Which department should you contact?
| Need | Department to identify | Useful document |
|---|---|---|
| Form 100 tax return | Competent tax office | Latest letter or tax assessment notice |
| Tax withholding card / Form 164 | Competent RTS office | Card and proof of the change |
| Annual tax adjustment (Form 163) | Competent RTS department | Request and certificates |
| Payment or refund | Relevant collection office | Statement and proof of transfer |
Do not mix up the identifiers
A person's identification number, the tax file number and the reference of a statement do not serve the same purpose. Use the label requested by the form or the official communication instead of assuming that every field expects the same number.
The year concerned must appear clearly in your message. For a payment, the reference must allow it to be allocated to the file and the right purpose; keep the proof without copying your data publicly.
Finding the right recipient
Check the ACD directory and the information in the letter you received. A change of address or situation can affect which office is competent. A former contact is not automatically the department in charge of the new procedure.
Fictitious example: Form 100 was processed by a tax office, but a question concerns the transfer of a tax advance payment. The tax calculation and the booking of the payment may require two checks with different departments.
A useful and safe message
- Subject: year and type of procedure.
- Reference: the one requested in the official letter.
- A precise question and relevant documents, through the accepted channel.
- No tax number, bank details or certificate in a public comment.
The firm’s other tax engagements
Depending on your situation, the firm also handles tax, VAT and payroll, the regularisation of late tax filings and assistance during a tax audit. Fees are listed in the firm’s fee grid.
Official sources and scope
The rules apply to the year and profile concerned. Examples flagged as fictitious explain a method; they are not an individual validation. The documents and options of your file are covered by a separate engagement.