Tax preparation cost in Luxembourg (2026)

A €260 dossier at TVA 17 % invoices at €304 all-in. Accountants and tax advisors are regulated services with no TVA 3 % route — the standard rate applies across all dossiers, both personal and professional.

What moves the dossier fee:

• Country coverage — adding a second country with its own tax credit and double-tax-treaty mechanics adds €80–€160 to the base
• Property holdings — each additional rental or second home adds €60–€120 in depreciation schedule and rental-income schedule preparation
• Stock compensation — LU has detailed rules on the taxable event of RSUs and stock options; an employee with those typically needs an extra €200–€350 of work
• Crypto or passive investment income — LU is one of the few EU regimes that still exempts long-held investment gains; declaring the exemption correctly requires careful documentation, adding €80–€150

Three professional categories in Luxembourg can prepare a tax return. Knowing which one fits the case avoids paying for a Ferrari when a sedan suffices.

Expert-comptable OEC (Ordre des Experts-Comptables):

• Full-scope professional registered with the OEC under the 1999 law
• Authorised to sign balance sheets, perform statutory audits for SMEs, represent clients before tax courts
• Rate typically €130–€220/hour, but personal returns quoted as flat fee
• Best fit: self-employed with company, SARL-S directors, complex cross-border cases, anyone needing court-level representation

Conseiller fiscal / tax advisor:

• Holds an Autorisation d'établissement for tax advisory; does not need OEC membership
• Cannot sign statutory audits or certify balance sheets
• Rate typically €90–€160/hour, flat fee for standard returns
• Best fit: employees, simple cross-border, individual returns with moderate complexity

Notaire:

• Used mainly for real-estate purchase tax calculations, succession (estate) tax filings, inheritance declarations
• Not used for annual income tax returns
• Flat fees set by the Chamber of Notaries; published schedule available

Which one for which case:

• Employee, one or two incomes, no business → tax advisor, €120–€260
• Cross-border, double-country, home loan → tax advisor or OEC, €250–€420
• Self-employed or company director → OEC expert-comptable, €450–€2 400/year
• Property sale with substantial capital gain → OEC + notary for the transaction
• Succession planning or estate declaration → notaire leads, possibly with OEC support

Red flags:

• A "tax firm" with no Autorisation d'établissement number and no OEC listing — walk away
• A flat fee quoted for a self-employed dossier below €400 — likely missing scope, expect add-ons
• Refusal to name the responsible practitioner on the invoice — compliance issue

A flat-fee personal dossier in Luxembourg includes the standard preparation pipeline, not every hour of tax advice. Ask what is in — and especially what is out — before signing.

Typically included in a €180–€300 dossier:

• Initial intake meeting (30 to 45 minutes, in person or video)
• Document checklist and secure upload portal
• Preparation of form 100 or 100 F with all standard schedules (rental, dividends, pension)
• Optimisation memo — where does the reduction sit, which deduction to maximise
• E-filing via MyGuichet.lu with the provider's practitioner access
• One follow-up round of questions from the Administration des contributions directes
• A final PDF package: filed return, computation, filing receipt

Usually not included:

• Multi-year review — scoping past three years for missed deductions, billed at €150–€250 per year reviewed
• Ruling request to the ACD on a disputed point — €450–€900 depending on complexity
• Representation before the Tribunal administratif on contested assessments — €150–€250/hour
• Bookkeeping for the self-employed beyond the annual return — €80–€140/month
• Payroll advisory for employer-structured packages — €120–€220/hour
• Second opinion on a prior-year filing by another advisor — €180–€320

Red flags:

• No written engagement letter — professional practice requires one; verbal-only engagements break OEC rules
• Fee structured as a percentage of tax refund — prohibited under Luxembourg practitioner ethics
• Aggressive "guaranteed" refund promises — LU tax law is deterministic; ethical advisors do not guarantee outcomes
• No invoice issued until the refund arrives — declared practitioners invoice on delivery, not contingent on refund

Luxembourg tax deadlines are forgiving compared to neighbouring countries but not infinitely elastic. The base deadline for annual income tax is 31 March of year N+1, extended to 31 December for residents and 31 March N+2 for non-residents on written extension request.

The deadline cycle for tax year 2025:

• 1 January 2026 — forms available on MyGuichet.lu
• 31 March 2026 — statutory deadline for filing personal returns
• 30 June 2026 — standard administrative extension, granted without formal request
• 31 December 2026 — deadline most practitioners work to
• 31 March 2027 — absolute final deadline for non-residents with extension

Consequences of late filing:

• First month late — reminder letter, no penalty
• Two to six months late — €50–€250 administrative penalty, compounding with interest on unpaid tax (0,6 % per month)
• More than six months late — penalty rises to €250–€1 250, automatic assessment estimated by the ACD (usually adverse)
• No filing at all — tax assessed on estimated basis, often 30–50 % above actual liability, and the burden flips to the taxpayer to prove otherwise

How practitioners space the work:

• January to March — employees with straightforward dossiers
• March to June — cross-border and multi-income cases
• June to October — self-employed annual accounts and complex cases
• October to December — late-arriving dossiers and amendments
• December — end-of-year rush; expect 10–15 % surcharge for December arrivals without prior retainer

Two practical tips:

• Book a slot in January for the following March. Most reputable firms give priority to January-booked dossiers.
• Keep a digital receipt folder through the year — quarterly uploads to the practitioner's portal speed up April intake and reduce the chance of missed deductions

Roughly half of Luxembourg's private-sector workforce lives in Germany, France or Belgium. Cross-border tax planning is therefore a routine service — but each of the three borders has distinct mechanics.

Germany border (Trier region):

• 183-day rule applies; days in Luxembourg must be counted precisely
• Pensions and dividends may be taxable in either country depending on the double-tax treaty
• Working-from-home days in Germany beyond 34 days per year can shift part of the salary to German taxation
• Practitioner must file both the LU form 100 F and the German Einkommensteuererklärung
• Typical dossier fee: €280–€450 for a couple

France border (Thionville, Metz):

• From 2024 onwards, up to 34 teleworking days per year stay LU-taxable; beyond that, the proportion shifts to France
• French solidarity-tax credit on LU income available via the Cerfa 2047
• Property holdings in France (residence principale or investment) file on the French 2044 declaration
• Typical dossier fee: €260–€420 for a single earner, €350–€550 for a couple

Belgium border (Arlon region):

• LU tax takes precedence on Luxembourg-sourced salary under the LU-BE treaty
• Belgian municipality tax still applies on worldwide income; the LU withholding is credited
• Home loan in Belgium may be deductible on both sides with coordination
• Typical dossier fee: €250–€400 for a single earner, €340–€520 for a couple

The Covid-era telework tolerances have now settled:

• Germany: 34 days
• France: 34 days
• Belgium: 34 days

Days beyond the tolerance shift taxation proportionally and trigger a second-country filing that most employees were not budgeting for. A practitioner familiar with all three treaties is not a luxury — it is the reason cross-border fees sit at €280–€500 for a dossier.

Three tax advisors quoting the same cross-border couple can land at €280, €420 and €620. The spread is real — and often reflects scope, not margin.

The six checks that matter:

• Practitioner type. OEC expert-comptable, declared conseiller fiscal or a generic "tax preparer"? The qualification shows on the invoice and limits what can be signed.
• Scope of what is priced. Federal income tax only, or also wealth declaration (impôt sur la fortune is no longer personal in LU but the check still matters for trusts) and municipality-level coordination?
• Treaty countries handled. A dossier that needs a German and a French filing beside LU is different from a single LU dossier.
• Round of follow-up included. Some quotes include one round of ACD questions; others bill per question at €60–€90 each.
• Prior-year review. A €420 dossier that includes a fresh look at the prior year is often better value than a €280 dossier that does not.
• E-filing included. MyGuichet.lu filing via the practitioner's access should be included; a dossier delivered as a PDF for the client to file themselves is a different service.

A clean briefing pack to send to three advisors:

• Household composition (marital status, tax class, dependants)
• Income sources (salary, rental, dividends, pension, stock compensation)
• Countries of residence and employment for the past 24 months
• Property holdings and home-loan details (country, interest paid, outstanding)
• Brokerage and investment statements
• Previous year filing PDF, if available
• Target deadline

Quotes on the same pack land within ±20 % on TTC. A wider spread almost always traces to scope differences — one firm spotted a missed cross-border element that another ignored. Five minutes on the phone with the mid-priced bidder usually surfaces the logic before signing.