What an accounting firm does, your bookkeeping obligations, how to choose one and what it really costs: the reference point for an SME director.

In short. An accounting firm in Luxembourg keeps a company's books, produces its tax and social filings, prepares its annual accounts and supports its management. For an SME, the point is not only to stay compliant, but to have accurate figures early enough to act on them. The market usually bills by the hour and rarely shows prices. At Advena, an SME's accounting starts at 325 € per month, all in, inside the management tool we deploy ourselves. This guide covers what you need to know before choosing.

"Fiduciaire", "accounting firm", "chartered accountant": the words blur together, and a director setting up or taking over a company does not always know what they are buying, or at what price. Here, without jargon, is what an accounting firm in Luxembourg covers, the obligations it takes off your plate, how to choose one and what the service really costs.

What is an accounting firm in Luxembourg?

An accounting firm keeps the books of third-party companies and supports them with their tax, social and legal obligations. It records transactions, prepares VAT returns, draws up the annual accounts filed with the trade register, runs payroll and advises the director on management. It is the accounting and tax counterpart of an SME that has no in-house finance team.

A useful point on wording: the titles of chartered accountant and statutory auditor are regulated professions, with reserved engagements such as statutory audit. An accounting firm, by contrast, handles day-to-day bookkeeping and support. At Advena we speak of an accounting firm and of accounting support, not of a regulated title we do not hold. Being straight on this point is part of the seriousness you are entitled to expect from a firm.

Your bookkeeping obligations as a Luxembourg SME

Before talking about the firm, you need to understand what the law expects of your company. A Luxembourg SME must, in essence:

  • Keep proper books under the standard chart of accounts, the PCN 2020.
  • File VAT at the right frequency for its turnover, through the eCDF platform, as we detail in our guide to VAT returns in Luxembourg.
  • Draw up and file its annual accounts with the trade register, on time, or face late-filing surcharges.
  • Pay its taxes on profit and on net wealth (CIT, MBT, net wealth tax), whose calculation we explain in our article on corporate tax in Luxembourg.
  • Keep its accounting records for ten years and be able to produce a FAIA file in the event of an audit.

None of these obligations is optional, and each has its own deadlines. This is exactly what an SME delegates when it hands its books to an accounting firm.

What does an accounting firm actually do for your SME?

A full engagement comes down to a few blocks. Day-to-day bookkeeping first: recording documents, reconciliation, bank matching. Then tax: periodic VAT returns, annual tax returns, deadline tracking. Then closing: drawing up the annual accounts and filing them with the trade register. Payroll and social filings often sit on top, followed by management advice: cash, margin, preparing decisions.

The real difference between two firms is not this list, which everyone offers, but the moment the information reaches you. A traditional firm often hands back the year's result the following spring. By then, the figures serve to confirm the past, not to decide. Real-time accounting, by contrast, gives you your position this month, while you can still act on it.

How much does an accounting firm cost in Luxembourg?

It is the most asked and worst-answered question, because almost no firm shows a price. The market's orders of magnitude are known, though: most bill by the hour, between 70 € and 300 € excluding VAT, and an SME's full annual budget often sits around 5,000 € excluding VAT, close to 415 €/month, before add-ons. We break down the billing models and their traps in our dedicated article on the price of an accounting firm in Luxembourg.

The Advena flat fee starts from 325 € per month, all in: day-to-day bookkeeping, VAT and eCDF filing, annual accounts and filing with the register, payroll, a monthly review with a dedicated file manager, a monthly report and permanent real-time access to your books. It is an entry point, reassessed above a certain volume or complexity, but always announced up front. Nothing is billed outside the monthly fee.

Want a figure for your own company, not a range? We put one on the table in a single conversation.

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How do you choose an accounting firm?

Beyond price, a few criteria separate a firm that saves you time from one that costs you. Pricing transparency first: a fee announced up front rather than an hourly meter. Then the freshness of the information: books kept current, not a snapshot of last year. A named contact, the same person month after month. And the ability to work inside your management tool rather than alongside it. We set out this grid in our article on how to choose the best accounting firm in Luxembourg.

Should you outsource your accounting?

For the vast majority of Luxembourg SMEs, the answer is yes: hiring an in-house accountant only makes sense above a certain volume, and outsourcing gives access to up-to-date expertise without a fixed cost. The real question is how to outsource without losing your grip on your figures. We answer it in our guide to outsourcing your accounting in Luxembourg.

The Advena difference: books kept in the tool we deploy

We are not a traditional accounting firm, and we are not a plain software integrator either. We do both, in the same tool. We keep your books in the Odoo we configured ourselves for the PCN 2020 chart of accounts, Luxembourg VAT and the FAIA export. In practice, this removes double entry, the year-end catch-up and the classic "we never got your documents". Your bank feeds and supplier invoices flow into the books continuously, and you read your position in real time, not eight months later. No traditional firm touches your ERP; no integrator keeps your books. That coupling is our difference, and it is described on the tool side in our Odoo in Luxembourg for SMEs guide.

Who this model is not for

Let us be plain. Our flat fee and real-time books are built for a Luxembourg SME of 1 to 50 employees that wants to steer, not just stay compliant. If you are a complex multi-jurisdiction holding with transfer-pricing questions, if your document volumes are unusually high, or if you simply want to drop off a box of invoices once a year at the lowest price, another model will suit you better. We would rather tell you at the first meeting.

Want accounting support that gives you your figures while they still matter? Let's talk.

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Frequently asked questions

What is the difference between an accounting firm and a chartered accountant?

An accounting firm keeps the books and supports the company with its day-to-day obligations. Chartered accountant and statutory auditor are regulated titles, with reserved engagements such as statutory audit. An SME usually entrusts its bookkeeping to an accounting firm.

Is an SME required to have an accounting firm?

No, nothing legally requires it. But it remains responsible for its books, VAT returns, annual accounts and taxes. In practice, with no in-house finance team, an SME outsources these obligations to an accounting firm.

How much does an accounting firm cost for an SME in Luxembourg?

The market often bills by the hour, between 70 and 300 euros, for a full annual budget frequently around 5,000 euros excluding VAT. The Advena flat fee starts from 325 euros per month, all in, with no hourly billing.

Can you change accounting firm easily?

Yes, at any time, observing the contractual notice period (often one to three months). The new firm recovers your records and picks up the file mid-year. It is a common scenario that suspends none of your obligations.

Do you need a particular software?

At Advena we keep your books in Odoo, configured for Luxembourg, and the tool is included in the engagement. If you already use another system, we discuss it: a migration is sometimes simple, sometimes unnecessary in the short term.

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Why Advena?

We are the only Luxembourg accounting firm that keeps your books in the management tool it deployed at your company. A fee announced up front from 325 € per month, a named file manager, books kept current at all times and not a single surprise line on an invoice. We inform, we invent nothing, and we tell you plainly when our model is not right for you.

Tell us where you stand, we tell you what it costs. No phantom quote.

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