Accounting Supporting Documents: What French Tax Law Requires

Quick answer. An accounting supporting document is any dated record that proves a transaction posted in the books (invoice, receipt, contract, statement). French tax law requires keeping it for six years (article L102 B of the Tax Procedures Code) and the Commercial Code for ten years. A scanned copy carries the same probative value as the original if it complies with article A102 B-2 of the LPF.

Every accounting entry tells a story, and that story must be provable. This is the whole purpose of the supporting document: without it, an expense is not deductible, input VAT cannot be recovered, and a set of accounts can be rejected during an audit. With the rollout of electronic invoicing and the scanning of expense claims, many business owners believe their records are secure when they are not. Here is what the tax authority actually expects from a supporting document, and how to give it real probative value.

A supporting document is the original, dated record that backs each accounting entry. The French General Accounting Plan requires that the books allow the accounts and statements subject to verification to be reconstructed from the supporting documents, and vice versa (article 911-3 of the PCG). This is the audit trail: an auditor or a tax inspector must be able to move from an entry to its supporting document without any break.

The invoice is the most common supporting document, but not the only one. Restaurant bills and till receipts, contracts, payslips, bank statements, tax notices, delivery notes and shareholder minutes are all supporting documents. The shared criterion is the ability to establish the reality, the amount and the date of a transaction.

Two families coexist. External supporting documents come from third parties (supplier invoices, statements). Internal supporting documents are produced by the company itself (sales invoices, payslips, vouchers). The former carry inherently stronger probative force, because they do not depend on the company alone.

Yes, provided a precise framework is respected. Since the order of 22 March 2017, a scanned paper invoice may be destroyed if its digital copy meets the requirements of article A102 B-2 of the LPF. This is one of the least understood points in the files we take over.

The scanning must guarantee an identical reproduction of the original: no image processing, lossless compression, and faithful colours where they carry information. The file must be kept in PDF or PDF A/3 format (ISO 19005-3 standard). Crucially, each scanned document must be secured by one of the following: a server seal, a digital fingerprint or an electronic signature based on a certificate compliant with at least the French General Security Framework (RGS) level one star. Finally, each file must be timestamped, at least by an internal source.

This is where the NF Z42-026 standard comes in, certifying compliant scanning services. A simple scan dropped into a shared folder, without fingerprint or timestamp, does not meet these conditions. It remains useful in practice, but its probative value can be challenged. For long-term retention, we cover the rules of probative electronic archiving in a dedicated article.

An invoice is only valid if it is complete. The mandatory mentions are set by article 242 nonies A of Annex II to the French Tax Code and by article L441-9 of the Commercial Code. In fact, the right to deduct VAT is conditional on holding an invoice that carries all these mentions (article 271, II of the CGI). An incomplete invoice means potentially non-recoverable VAT.

The mentions to check systematically:

1. Full identity of the seller and the buyer (name, address, company registration number).
2. A unique invoice number following a continuous chronological sequence.
3. Issue date and transaction date (delivery or service).
4. Precise description and quantity of the goods or services.
5. Unit price excluding tax, applicable VAT rate and VAT amount per rate.
6. Intra-Community VAT number of the seller (and of the buyer in reverse-charge cases).
7. Payment terms and late-payment penalties.

A tolerance exists: invoices with a total amount of 150 euros or less excluding tax may omit certain mentions, including the VAT number (BOI-TVA-DECLA-30-20-20-20). This simplification does not, however, waive the essential mentions identifying the transaction. The concept of a receipted invoice follows a different logic: it proves payment, not deductibility.

Missing supporting documents are among the first issues flagged during an audit. The default rule is clear: no document, no deduction, and a risk that both the expense and the VAT are challenged. But reconstitution solutions exist, provided they are documented and remain the exception.

For a lost invoice, the first step is to request a duplicate from the supplier: this is the only record that fully restores probative value. Failing that, a body of evidence can support the reality of the expense: purchase order, bank statement, contract, email exchange. This does not guarantee VAT recovery, which remains strictly tied to the invoice, but it can secure the corporate-tax deductibility of the expense.

Some small expenses (parking, tolls, tips) sometimes have no formal document at all. A dated, signed internal note stating the purpose, the amount and the business nature is then the minimum to produce. It does not replace an invoice, but it creates traceability. In our bookkeeping and accounts review engagements, we formalise these procedures to avoid gaps in supporting documents at year-end.

Two periods coexist and must not be confused. The tax period is six years from the last transaction or from the date the document was drawn up (article L102 B of the LPF). The accounting period, set by article L123-22 of the Commercial Code, is ten years. In practice, the longer period prevails: we recommend keeping all records for ten years.

One key point on the retention format: a document received electronically must be kept electronically for the entire period. You cannot print it and then discard the digital original. Our retention-period table for company documents sets out these obligations case by case.

Micro-entrepreneurs and independent professionals. Even under the VAT exemption, the obligation to keep supporting documents remains. The micro-entrepreneur deducts no expenses but must be able to justify revenue: missing documents weaken the return in the event of an audit.

Retailers and restaurateurs. Till receipts and the daily revenue breakdown are full-fledged supporting documents. For retailers and points of sale, keeping the cash journal and ensuring cash-register software compliance are frequent control points.

Corporate-tax companies and dividends. Distributing dividends, taxed under the flat tax at 31.4% in 2026, requires shareholder minutes and approved accounts: these too are supporting documents.

The rollout of electronic invoicing changes the picture. From 1 September 2026, every VAT-registered business must be able to receive electronic invoices; large companies and mid-sized companies must also issue them. Small and medium businesses follow on 1 September 2027. The invoice becomes a structured data flow, and its probative value will depend on the compliance of the platform used.

We flag three recurring mistakes. First: keeping the scan and discarding the original electronic invoice, when it is the electronic original that prevails. Second: scanning without fingerprint or timestamp, which strips the copy of probative value. Third: a broken audit trail, where an entry can no longer be linked to its supporting document. Our support for the 2026 electronic-invoicing reform addresses these points precisely ahead of the deadline.

What the tax authority looks at#

During an audit, the inspector first tests the consistency of the accounting entries file (FEC) against the supporting documents. They then verify that the most significant expenses are backed by compliant invoices, that deducted VAT rests on valid documents, and that scanned records comply with article A102 B-2. Accounts lacking probative supporting documents risk rejection and a reconstruction of taxable profit.

Our take. Probative value is not decided at the moment of an audit: it is built upstream, in the way each document is captured, named and archived. The files that fare best in an audit are not those with the most documents, but those where each entry points to a supporting document identifiable in seconds.

The underestimated risk. Many directors believe a scan in the cloud is enough. Yet an unsecured PDF does not carry the probative value of article A102 B-2: it is tolerated, but legally fragile. The day the paper original has gone and the copy is neither timestamped nor sealed, the expense becomes challengeable. It is a silent risk that surfaces only during an audit.

Recently, the director of a trading company came to us after an initial accounting review in which the inspector had set aside several thousand euros of expenses for lack of recoverable invoices. The expenses were genuine, paid by transfer, but the supporting documents had been destroyed after a simple, unsecured scan. We rebuilt a body of evidence and obtained duplicates, but part of the VAT was permanently lost. Everything would have been secured by compliant scanning from the outset.

As chartered accountants registered with the Order and statutory auditors, we apply this audit-trail requirement in our bookkeeping engagements as well as in our statutory audit engagements. To streamline capture, we equip our clients with a document-capture tool, Dext that links each supporting document to its entry.

Hayot Expertise tip. Set up compliant scanning today, do not wait for an audit. Choose a solution that timestamps and seals files, keep electronic originals as they are, and enforce one simple rule: no entry without an attached document. It is the best investment in peace of mind for your next ten years of operation.