DAC8 for Accounting Firms

DAC8 puts no reporting obligation on accounting firms, which is exactly why it is easy to underestimate from a practice's seat. The catch is subtler: from FY 2026 the tax authority holds an independent CASP-reported data feed that every crypto client's return is silently checked against. That turns the firm's job from "compute and file" into "compute, reconcile against what the authority will independently see, and document the difference." This article is for the practice specifically — the new reconciliation step, how to standardize it, and how to re-scope crypto engagements around it. The underlying CASP obligation that generates the feed is covered in the data-collected reference and the individual-holder view.

The practice impact in short

• There is no direct DAC8 obligation for firms unless the firm is itself a CASP. The change is a new reconciliation duty.
• The workflow gains a step: reconcile the client's books against what CASPs will have reported, before filing.
• The first cross-check is FY 2026 returns, against data exchanged by 30 September 2027.
• Build a standard procedure: collect access, normalize, estimate CASP-reported figures, compare, investigate discrepancies against a firm-set materiality threshold, document in the client file.
• Re-scope and re-price crypto clients to reflect the added reconciliation work.

The workflow change, precisely

The pre-DAC8 crypto-client workflow:

1. Collect client wallet addresses and exchange access.
2. Reconstruct and compute gains/income under the relevant national rules.
3. File the return.

The post-DAC8 workflow adds a reconciliation step that is not optional in practice:

1. Collect client wallet addresses and exchange access.
2. Reconstruct and compute gains/income.
3. Estimate what each CASP will have reported for the client (aggregate acquired/disposed against fiat and crypto, transfers).
4. Reconcile the computed position against the estimated CASP figures.
5. Investigate material discrepancies — missing wallet, mis-classified counterparty, timing differences — before filing.
6. Document the reconciliation in the client file.
7. File the return.

Steps 3–6 are new. They exist because, from FY 2026, the authority receives the CASP data independently and a mismatch with the filed return is an automatic flag (see DAC8 impact on individuals).

What a standard DAC8 reconciliation procedure looks like

A practice handling multiple crypto clients should standardize this rather than improvising per client:

The materiality threshold is a firm policy, not a regulatory number — do not adopt an invented "X% / €Y" figure as if it were prescribed. Set it, document it, apply it consistently.

Professional exposure, framed correctly

The firm's exposure is not a DAC8 fine — that sits on CASPs. It is professional:

• A return that materially diverges from CASP-reported data without a documented basis is a quality-of-work and diligence problem.
• "We computed from the client's data" is no longer a complete answer when the authority has independent data the firm did not reconcile against.
• The documented reconciliation is what demonstrates the firm did its job.

This reframes DAC8 for a practice: it is a client-file diligence and professional-risk matter, managed with a standard procedure, not a new filing.

Re-scoping and re-pricing crypto clients

The added steps are real work. A crypto client in 2026 requires:

• History reconstruction (often multi-year, multi-chain)
• Ongoing transaction normalization
• An annual DAC8 cross-check and discrepancy investigation
• Reconciliation documentation

Firms typically move crypto clients off a flat return fee onto a scoped engagement that reflects transaction volume and chain/protocol complexity. The DAC8 reconciliation is a recurring annual line, not a one-off. Pricing that does not account for it underprices the engagement and absorbs the professional risk for free.

Reporting Obligations by Client Type

Not all crypto clients create the same DAC8 exposure for an accounting firm. The nature of the client determines both the reconciliation complexity and the professional risk surface.

Individual Investor Clients

For an individual with exchange accounts at one or two EU-authorized CASPs and no DeFi activity, the DAC8 reconciliation is relatively contained: the CASP will report aggregate acquired and disposed figures per asset. The firm's reconciliation exercise is verifying that the declared K4 (Sweden), Form 2086 (France), Appendix SO (Finland), or equivalent matches the expected CASP aggregates within a reasonable materiality tolerance.

The main wrinkle is self-custody: assets moved off exchange to a hardware wallet or non-custodial software wallet drop off the CASP's books at the point of withdrawal. The CASP reports the withdrawal as a transfer; the tax authority sees the transfer but not the subsequent on-chain activity. The individual is responsible for declaring gains from self-custodied disposals. A filing that reconciles to CASP-reported data without accounting for self-custodied activity will have an apparent gap — a withdrawal that never came back on-chain as a taxable disposal. Firms should add a standard self-custody questionnaire to the client intake.

High-Volume Individual Traders

A client who traded DeFi protocols across multiple chains in addition to centralized exchanges represents a materially higher reconciliation effort. CASPs will report only centralized exchange activity; DeFi protocol interactions — swaps through automated market makers, liquidity pool deposits and withdrawals, yield farming — generate taxable events in most jurisdictions but are not subject to CASP reporting. The declared position should therefore be larger than what the CASP-reported data shows. A filed return that matches the CASP data closely for a DeFi-active trader may be under-declared — the DAC8 cross-check creates a floor, not a ceiling.

Corporate Crypto Clients

Corporate clients operating with crypto — treasury holdings, on-chain payroll, DeFi activity, token issuance — require the most extensive DAC8 reconciliation framework. The corporate book is the ANC/PCG (France), HGB (Germany), or relevant GAAP ledger; the CASP-reported figures are per-entity user data at the CASP. A mid-size company with multiple wallet addresses and accounts at several exchanges requires the firm to:

1. Map all CASP accounts to the entity's books (wallet inventory reconciliation).
2. Estimate aggregate CASP-reported figures across all accounts for the entity.
3. Compare the company's ledger-derived gains/income figures to those estimates.
4. Investigate gaps from intercompany transfers, DeFi activity, or unhosted wallet flows.

The professional exposure is higher for corporate clients: a material discrepancy in a company's accounts can trigger a vérification de comptabilité (France) or equivalent full accounting audit, not just an income-return adjustment.

Firm Clients Who Are CASPs

If an accounting firm has clients that are themselves CASPs, those clients carry both the CASP reporting obligation and the accounting firm relationship. The firm's role here is dual: preparing the client's accounts correctly (including treating the DAC8 reporting cost as a business expense) and verifying the client's own DAC8 filings are complete. The firm should have separate engagement terms for CASP clients reflecting the distinct compliance obligations.

Where vendors fit

• Cryptio is the transaction-normalization layer many practices standardize on for multi-client crypto books.
• TaxBit produces the reporting-shaped figures useful for estimating the CASP-side numbers.
• Sumsub is relevant where the firm advises CASP clients on the due-diligence side.

The reconciliation judgement — materiality, discrepancy investigation — remains the firm's, supported by but not replaced by tooling.

Where Wag3s sits in the practice workflow

The new reconciliation step is data work the firm now repeats per client, per year, so it benefits from a single multi-client surface. Wag3s Ledger is built for that:

• Multi-client, multi-chain reconciliation from a single admin surface (see multi-chain reconciliation)
• Per-jurisdiction cost-basis computation (FIFO/LIFO/PMP)
• Per-user aggregation matching the DAC8 reportable categories, to estimate the CASP-side figures
• Retained lineage so the reconciliation memo is supported by traceable data

The materiality threshold, the discrepancy judgement, and the professional opinion stay with the firm — Wag3s supports the practitioner's reconciliation rather than substituting for it. See the Wag3s for accountants page and the Ledger product page.

Further reading

• DAC8 Compliance Guide 2026
• DAC8 Data Collected
• DAC8 Impact on Individuals
• Crypto Accounting Pennylane Export
• Crypto Audit Readiness
• Multi-Chain Reconciliation

Sources

• Council Directive (EU) 2023/2226 (DAC8) — EUR-Lex
• European Commission — DAC8 overview
• OECD Crypto-Asset Reporting Framework — model rules and commentary