The FEC (French accounting audit file): what it is and how to request it from a client

What the FEC actually is

The Fichier des Écritures Comptables (FEC) is a complete, line-by-line export of every accounting entry recorded during a fiscal year, in a standardized plain-text format. Since 2014, any business subject to a French tax audit has had to be able to hand this file over to the tax authority (DGFiP) on request.

The point of the format is to let auditors work directly with the data — running their own cross-checks, sampling, and consistency tests — rather than reviewing printed ledgers or PDF exports that differ from one piece of software to the next. Every FEC follows the same 18-column structure, whatever accounting software produced it.

Who has to be able to provide one

The obligation applies broadly: any company subject to corporate tax (impôt sur les sociétés), and any professional or business taxed on business income (BIC, BNC or BA) under an actual taxation regime (régime réel), must be able to produce a FEC covering the period being audited — provided their bookkeeping is computerized, which today is virtually always the case.

A few situations sit outside the obligation, notably very small businesses under a simplified micro-entrepreneur regime with cash-basis reporting and no computerized ledger to speak of. In practice, though, if a client uses accounting software at all — even a basic one — the firm should assume a FEC will eventually be requested.

When accountants actually need it

Two situations account for most FEC requests a firm handles. The first, and by far the most time-sensitive, is a tax audit: once the client receives a formal audit notice (avis de vérification), the FEC covering the relevant fiscal years typically has to be handed over within about 15 days of the auditor's request. Missing that window, or handing over a file that gets rejected on a technicality, creates friction with the tax authority right at the start of the audit.

The second situation is quieter but just as common: taking over a new client's file from another firm, or migrating them onto new software. Pulling the prior year's FEC lets the incoming firm check that opening balances, journal structure and entry numbering line up with what the client believes was recorded — before problems surface months later.

How the client generates the file

The FEC is exported directly from whatever accounting software holds the client's books — Sage, Cegid, EBP, Quadratus and most others include a dedicated export function, usually tucked under a menu labelled something like "FEC export" or "tax audit file". If the firm manages the client's bookkeeping itself, this is a non-issue: the firm generates the file in-house.

The friction shows up when the client keeps their own accounts in-house, on software the firm doesn't have access to. In that case, the request has to go to the client directly, and it's rarely obvious to them where the export function even sits in their software — which is exactly where a clear, step-by-step request pays off.

• Client-managed bookkeeping: the firm has to request the export from the client, who runs it from their own software
• Firm-managed bookkeeping: the firm generates the FEC directly, no client involvement needed
• Software migrations: always pull a FEC from the outgoing system before switching, as a reference snapshot

The mandatory file name and structure

The FEC follows a fixed naming convention: siren_FECYYYYMMDD.txt, where siren is the company's 9-digit SIREN number and the date is the fiscal year's closing date. A tax auditor who receives a file with the wrong name, or the wrong date, will flag it before even opening it.

Inside the file, entries are laid out one per line, generally tab-separated, across 18 mandatory columns: journal code and label, entry number and date, account number and label, auxiliary account references, document reference and date, entry description, debit and credit amounts, reconciliation references, validation date, and foreign-currency amount and code where relevant. The order and naming of these columns is fixed — renaming a column, even to something equivalent, is treated as non-compliant.

Common reasons a FEC gets rejected

Most FEC rejections have nothing to do with the accounting itself — they're formatting issues that a quick check would have caught before submission.

• Wrong character encoding, producing garbled accented characters when the file is opened
• Decimal separator using a comma where the format expects a point, or vice versa
• Dates not formatted as YYYYMMDD
• Missing, renamed or reordered mandatory columns
• Entries that don't balance — total debits and total credits don't match
• Wrong file extension, delimiter, or a file re-saved through spreadsheet software that silently altered the formatting

How the firm should validate it before submitting

Before a FEC goes anywhere near a tax auditor, it's worth running it through a validation pass — free testing tools exist for exactly this (including one published by the tax authority itself), and they catch most structural issues in seconds. Beyond the automated check, it's worth confirming manually that total debits equal total credits, that entry numbering runs without unexplained gaps, and that journal codes match the client's actual chart of accounts.

Doing this the moment the file arrives, rather than the day before the deadline, leaves enough room to go back to the client if something looks off — which is far better than discovering a formatting problem with two days left on a 15-day clock.

Getting the file from the client without the email back-and-forth

We've covered the broader list of documents to request from a new accounting client in a separate article — company, financial, tax and payroll records, gathered at onboarding or at each year-end. The FEC deserves its own treatment here because it behaves differently from most of those documents: it's software-specific, it's technical for a client who isn't an accountant, and it usually needs to move fast once an audit notice has landed.

In practice, the fix is the same one that works for any recurring, deadline-driven request: a clear checklist that tells the client exactly what to export and from where, sent through a channel that tracks whether it's been done, with automatic reminders instead of a manual follow-up email three days before the deadline. When the file lands, the firm can validate it immediately and, if it's malformed, bounce it back with a specific note rather than trying to patch it manually — which keeps the 15-day clock from becoming the firm's problem to solve alone.