Declaring Crypto in France With an Accountant

The companion question to "can I self-file?" is "when should I not?" Most occasional investors can file themselves, as the self-filing guide sets out. This article draws the honest decision boundary on the other side: the specific situations where an expert-comptable earns the fee, what the cabinet actually does, and how a crypto engagement is scoped in 2026. It connects to the occasional-versus-professional question that often drives the decision, and to the France crypto tax guide for the underlying regime.

Self-file or cabinet, in brief

• Self-file if you are a straightforward occasional investor with manageable activity.
• Use a cabinet if any of these apply: professional/BNC risk, high volume or many chains, substantial staking/DeFi income (BNC), prior unreported years, an exit/residency question, or a company holding crypto (FEC).
• The cabinet reconstructs and reconciles, classifies (PFU versus BNC), prepares 2086/3916-bis/2042 C (or the BNC declaration / déclaration contrôlée / FEC), documents the position, and runs the DAC8 reconciliation.
• Pricing is scoped to complexity (volume, chains, DeFi, company), not asset value.
• DAC8 from 2026 adds a reconciliation step the cabinet operationalises; it does not disappear.

When the expert-comptable is worth it

The decision is not "rich vs not" — it is complexity and risk. Engage a cabinet when any of these is true:

If none apply, self-filing is appropriate and the cabinet fee is avoidable. The error in both directions is real: self-filing a professional/BNC position botches it; paying a cabinet for a two-disposal occasional year over-spends.

What the cabinet actually does

A French crypto engagement is not "fill in the form." It is:

1. Reconstruct and reconcile the full multi-year, multi-chain history.
2. Classify: occasional (PFU/150 VH bis) vs professional (BNC) vs reward income (BNC at receipt).
3. Compute: gains under article 150 VH bis; reward income under BNC; losses (intra-year, see loss treatment).
4. Prepare: Form 2086, 3916-bis, carry to 2042 C — or the BNC declaration / déclaration contrôlée and FEC for a company.
5. Document the occasional/professional position (the audit-defence file).
6. Reconcile against DAC8-reported data (from 2026) and investigate material discrepancies.

Step 5 and step 6 are where the cabinet's value over a tool is clearest — the judgement and the documented defence, not the arithmetic.

How the engagement is scoped and priced

Pricing tracks complexity, not asset value:

• One-off: history reconstruction (often multi-year) — usually the largest cost.
• Recurring annual: the return (2086/3916-bis/2042 C or BNC/FEC) + the new DAC8 reconciliation step.
• Drivers: transaction volume, number of wallets/chains, DeFi/LP/staking complexity, company-vs-individual.

A flat "crypto return" fee that ignores volume and DeFi complexity underprices the work and absorbs the professional risk for free — expect a scoped quote.

Prior unreported years: the regularisation case

The clearest "use a cabinet/lawyer" case is prior unreported years. Given the 10-year reassessment window for omitted activity/accounts and DAC8 detection from 2026 (see DGFiP audit), a voluntary déclaration rectificative before the first DAC8 cross-check generally yields a materially better outcome than a discovered omission. This is national-tax-law work — not a self-filing or tool task.

DAC8 makes the cabinet step heavier, not optional

From 2026 the DGFiP receives CASP-reported data automatically. The cabinet's workflow gains a mandatory reconciliation step: client books vs reported data, investigate material discrepancies against a documented (firm-set) threshold, record it in the client file. Using a cabinet means this is done and documented properly — it does not remove the duty (see DAC8 for accounting firms for the practice-side view).

What to prepare before your first meeting

Bringing a complete dossier to the first engagement meeting reduces the cabinet's reconstruction cost and therefore your fee. The key items:

Transaction history exports: export CSVs from every exchange you have used, covering all years. Most major exchanges (Binance, Coinbase, Kraken) provide a complete trade history export. Do this before the meeting — the cabinet cannot reconstruct exchange history if you no longer have access to the account.

Wallet addresses: list all wallet addresses you have used, on all chains. Include any DeFi wallets, multisig addresses, and hardware wallet public keys. For each, note the approximate first-use date and the current approximate balance, if any.

Prior tax returns: bring the last three to five years' déclarations des revenus, including any Cerfa 2086 or 3916-bis you filed. If you did not file them when you should have, say so — the cabinet needs to know the disclosure gap to advise correctly.

Reward sources: identify any staking, mining, DeFi farming, or airdrop activity, with the approximate protocol and approximate amounts. These are BNC income items and require valuation at receipt — the more organised your records, the cheaper the BNC computation.

Entity structure: if you have a French company holding crypto, bring the SIREN, the last balance sheet, and the current token holdings by entity.

The cabinet's first task is usually history reconstruction — and everything you can bring reduces the hours needed.

Practical guidance

1. Run the decision table — if any high-risk row applies, engage a cabinet.
2. Expect a scoped quote (volume/chains/DeFi/company), not a flat fee.
3. Bring a clean history — a reconstructable record lowers the cabinet's cost and your risk.
4. Regularise prior years with counsel ahead of the DAC8 cross-check.
5. Confirm the cabinet runs the DAC8 reconciliation and documents it.

Where a tool fits alongside a cabinet

Waltio (built for the French market) and Koinly produce the 150 VH bis figures the cabinet validates and builds on. Tools and cabinet are complementary here, not alternatives: the tool does the arithmetic and history, while the cabinet does the classification judgement, the documented defence, and the DAC8 reconciliation.

Where Wag3s fits

Wag3s Folio gives the cabinet and the client a continuously reconcilable multi-chain history with 150 VH bis figures and listed foreign accounts; for company clients, Wag3s Ledger provides FEC-ready records, lowering the cabinet's reconstruction cost and supporting the DAC8 reconciliation. Wag3s is explicitly the records-and-figures layer the cabinet works from; the classification judgement, the documented audit defence, and any prior-year regularisation remain the expert-comptable's. See the Folio and Ledger pages, and the Wag3s for accountants page.

Further reading

• Declare Crypto Without an Accountant (France) — the self-file counterpart
• France Crypto Tax Guide 2026
• Occasional vs Habitual Trader (France)
• BNC vs PFU for Crypto in France
• DGFiP Crypto Tax Audit
• DAC8 for Accounting Firms

Sources

• Légifrance — Article 150 VH bis CGI: the occasional-investor disposal regime (the PFU/2086 side).
• Légifrance — Article 92 CGI: bénéfices non commerciaux, the basis for professional trading and reward income.
• BOFiP — RPPM, cession d'actifs numériques à titre occasionnel : modalités d'imposition et obligations déclaratives (BOI-RPPM-PVBMC-30-30): the doctrine the cabinet substantiates the filing against.
• Council Directive (EU) 2023/2226 (DAC8) — EUR-Lex.