Choosing accounting software with a fiduciaire

The five questions to ask the fiduciaire before you buy

1. Which software do you work in, and what exactly do you want from me? There are three honest answers and they cost you very different amounts: a shared cloud tenant where you both work in the same ledger, a file or API handover where you export and they import, or a bag of PDFs that somebody types in. Ask which one they mean, and ask what they charge for each. The third one is the expensive one, and the cost lands on you.

2. Who produces the FAIA file, and out of which system? Not "can it do FAIA", but who presses the button, from which database, and for which years. If your sales live in a till or a web shop and your ledger lives at the fiduciaire, the single-file rule becomes an integration question, not a feature checkbox. Ask them to produce a FAIA file from a demo or from a comparable client before you sign.

3. Who files the eCDF VAT return and validates the annual accounts, and what do you need from me? Clarify whether they file in their own eCDF access or in yours, and what the handover looks like: an XML export from your software, a trial balance in their format, or read access to your system. Also agree who watches the filing frequency, which moves with turnover: annual only below 112 000 euros, quarterly up to 620 000 euros, monthly above.

4. How do bank statements and supplier invoices reach you? Ask for the formats by name. CAMT.053 and MT940 for bank statements, a structured feed or a scan folder for purchase invoices, and what happens with receipts that arrive as photos. A fiduciaire that can only take CSV exports will quietly re-key your bank line by line. Ask about the formats per country too, not just per product: one Benelux package documents that CODA import does not work on a Luxembourg legislation file even though it works on a Belgian one.

5. What happens when we part ways? Who owns the licence, who owns the data, in which format do you get it back, how long do they keep the archive, and what does the export cost. Get this in writing while they still want the engagement. Note also that accounting documents have to be kept available for ten years, so "we deleted it" is not an acceptable answer.

The question to ask yourself instead of the fiduciaire

Your invoicing, your till and your incoming-invoice intake are yours, not theirs. A fiduciaire optimises for clean postings arriving on time, which is a perfectly good objective and not the same as your objective, which is getting invoices out and getting paid. If the bottleneck in your month is issuing invoices rather than closing the books, pick the front office tool on its own merits and ask the fiduciaire only whether they can consume its output. Our invoicing software comparison for freelancers in Europe is built on exactly that split.

Disclosure, so you can weigh this paragraph accordingly: the publisher of this site also builds LUXPOS, a Luxembourg point of sale with an invoicing and incoming-invoice side. It is not ranked anywhere in this accounting vertical, and the general point stands whichever front office you choose: pre-coded incoming invoices reduce what the fiduciaire has to type, and typing is what you pay for.

What changes in 2028, and what to put in the contract now

Electronic invoicing is already compulsory towards the public sector. Since 18 March 2023, every economic operator, with no exception for size or invoice amount, has to transmit invoices to Luxembourg public bodies as a compliant electronic invoice through Peppol or through MyGuichet.lu, not by email.

For business to business, bill 8815 was deposited in the Chamber of Deputies on 30 July 2026. It transposes article 1 of Council Directive (EU) 2025/516 and, as deposited, enters into force on 1 January 2028, with the obligation to issue compliant electronic invoices arriving at the latest on 1 July 2028 for issuers that exceeded at least two of three thresholds at their 2026 balance sheet date, 7 500 000 euros of balance sheet total, 15 000 000 euros of net turnover or 50 full time employees, and at the latest on 1 January 2029 for everybody else. It is a bill, not law, and the text as deposited names a "common delivery network" and the European e-invoicing standard rather than a brand, leaving the technical parameters to a grand-ducal regulation.

Two practical consequences. First, do not pay a premium today for a 2028 compliance promise written against a bill that can still change. Second, do write into the contract that the vendor will support the Luxembourg e-invoicing obligation at no extra licence cost when the law is published, and that your data comes back in a structured format if they do not. For the rate logic your software has to reproduce either way, see which VAT rates apply in Luxembourg, and for the shortlist itself, the best accounting software for Luxembourg.

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