Tax advisor in Luxembourg, returns, compliance and documented positions.
"Tax advisor" is not a regulated title in Luxembourg: it is a function, performed by a licensed accountant, an expert-comptable registered with the OEC or a tax lawyer depending on the case. Financial Services Luxembourg acts as a licensed accountant: we prepare your tax returns, secure compliance and document the positions taken. Services reserved to the expert-comptable and legal tax advice are coordinated with duly qualified professionals, without you changing contact.
A tax advisor handles the tax obligations of a company or an individual: preparing returns, computing the tax charge, meeting deadlines and supporting positions in the event of an audit. In Luxembourg the function carries no protected title, but its exercise is regulated: each professional acts within the limits of their business licence or professional body.
Amended law of 2 September 2011 on the right of establishment: the accountant prepares tax returns for legal entities and individuals and may not perform services reserved to the expert-comptable (source: "Comptable" factsheet, guichet.public.lu). Amended law of 10 June 1999: the expert-comptable title is reserved to members of the Ordre des Experts-Comptables. FSL holds licences 10077274/0 (accountant) and 10077274/2 (ancillary activities), verifiable on guichet.public.lu.
Key takeaway
- "Tax advisor" is a function, not a protected title in Luxembourg.
- A licensed accountant prepares returns for both entities and individuals.
- Services reserved to the expert-comptable and legal advice fall outside that scope: we coordinate them.
- The deadline to challenge a tax assessment is three months (§ 228 AO).
Why "who is my tax advisor" is the wrong question
Most Luxembourg companies look for a tax advisor when they actually need three distinct things: someone to produce returns on time, someone to arbitrate uncertain positions, and someone to defend them in a dispute. These do not call for the same professional, nor the same budget.
Producing returns is compliance work, anchored in the annual accounts: it is the core of the licensed accountant role. Arbitrating complex positions and giving legal tax advice fall to the expert-comptable or the lawyer. Conflating the three means either paying lawyer rates for a routine filing, or handling in-house a question that deserved an opinion.
What our engagement covers, and what it does not
We prepare corporate and personal tax returns and VAT returns, and we track assessments and advances. We document the positions taken, which is the only real protection under audit: a defensible but undocumented position defends poorly.
We do not perform services reserved to the expert-comptable and we do not issue legal tax opinions. When your file calls for a formal opinion, an advance decision or litigation representation, we prepare the technical file and hand it to the qualified professional. You keep a single contact and you do not pay twice for the same analysis.
The three points where a tax file goes wrong
The first is late filing. An unfiled return exposes you to an assessment on an estimated basis, almost always unfavourable. Catching up costs more than routine production, and challenging it turns on short deadlines.
The second is inconsistency between the accounts filed with the RCS and the tax return. Both data sets are available to the administration: an unexplained gap is an invitation to audit. The consistency check between annual accounts and the return is part of our routine work.
The third is a tax assessment received and filed away unread. The claim deadline is three months from notification (§ 228 of the General Tax Law). After that, even an obvious error becomes very hard to correct.
Tax advisor, accountant, expert-comptable, lawyer: who does what?
| Licensed accountant (FSL) | Expert-comptable (OEC) | Tax lawyer | |
|---|---|---|---|
| Regulated title | No, business licence | Yes, registered with the Ordre | Yes, registered with the Bar |
| Tax returns | Yes, entities and individuals | Yes | Possible, rarely the core engagement |
| Services reserved to the OEC | No | Yes | No |
| Legal tax opinion | No, coordinated with a lawyer | Depending on the engagement | Yes |
| Litigation and claims | File preparation | Depending on the engagement | Representation |
Sources: official texts cited on this page. Summary: Financial Services Luxembourg, licensed accountant.
Who it is for
- Luxembourg companies wanting a single contact for their filings
- Directors and self-employed whose personal and business positions overlap
- Foreign groups with a Luxembourg subsidiary or holding
- Companies behind on filings or under audit
What we do
- Corporate tax returns (form 500): CIT, municipal business tax and net wealth tax
- Personal tax returns (form 100), including cross-border situations
- VAT registration, periodic returns and annual VAT return
- Quarterly advance computation and deadline tracking
- Consistency check between filed annual accounts and the tax return
- Documentary assistance for information requests from the ACD or AED
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Preparation checklist
Get the list of documents and steps to start without friction.
The process, step by step
Scoping
Review of the tax position: legal form, open years, late filings, ongoing audits. We tell you upfront what falls within our scope and what calls for an expert-comptable or a lawyer.
File handover
Recovery of prior returns, tax assessments and ACD correspondence. Reconstruction of the positions taken by the previous provider.
Preparation
Returns prepared from the annual accounts, with a consistency check between the tax return and the accounts filed with the RCS.
Approval
You review, we document every significant position before filing. An undocumented position is an indefensible position under audit.
Follow-up
Assessment checks on receipt, verification of advances called, alerts on claim deadlines.
Official sources and verification
This page is written and reviewed by Mickaël LOC, licensed accountant in Luxembourg (business permit 10077274). The rules cited can be checked with the competent authorities.
Frequently asked questions
Is the tax advisor title regulated in Luxembourg?
No. Unlike "expert-comptable" and "réviseur d'entreprises agréé", which are protected titles, "tax advisor" describes a function. What is regulated is its exercise: each professional acts within the limits of their business licence or professional body.
Can an accountant prepare my tax returns?
Yes. The "Comptable" factsheet on guichet.public.lu states that the accountant prepares balance sheets and tax returns for legal entities and individuals, without performing services reserved to the expert-comptable.
What happens if my file needs a legal tax opinion?
We prepare the technical file and hand it to a lawyer or an expert-comptable registered with the OEC. You keep a single contact and the analysis is not duplicated.
How long do I have to challenge a tax assessment?
Three months from notification, by claim addressed to the director of the Direct Tax Administration (§ 228 of the General Tax Law). We check assessments on receipt precisely so that this deadline does not lapse.
Do you take on files with late returns?
Yes. We start by listing open years and any estimated assessments, then prioritise according to the remaining challenge deadlines.
Request a quote
Reply within 24 business hours. NDA from first contact.