Vienna 3.0

The Vienna 3.0 DARTE session took place on May 18th, 2026, at the Web3 Hub Vienna, in collaboration with the European Commission, Vienna Blockchain Week, and 3Folio. This edition brought together regulators, legal practitioners, and digital asset infrastructure providers to examine the accounting and tax reporting challenges emerging as Web3 activity scales and the DAC8 reporting regime moves toward implementation.

The roundtable explored three interconnected themes. The session opened with an introduction to the DARTE concept by Mariana de la Roche (BlackVogel) and an overview of the OSCE's virtual asset related work by Zurab Sanikidze (OSCE). Michael Schöngruber (3Folio) then examined why traditional accounting and ERP systems fail to scale for Web3 transactions, and the case for a dedicated upstream system to keep books auditable and operationally manageable. Marie Rinke (Möhrle Happ Luther) followed with an analysis of the information asymmetries between users and tax authorities under DAC8 reporting, and the transparency and correction mechanisms needed to protect taxpayers. Benjamin Fassl (PwC) closed the technical sessions with a discussion of the classification and conversion challenges inherent in DAC8/CARF reporting, and the practical simplifications that could reduce divergent outcomes across providers. The session concluded with closing remarks by Dr. Nina-Luisa Siedler.

The Vienna 3.0 edition reinforced DARTE's role as a venue for grounded, multi-stakeholder dialogue on the operational realities of digital asset regulation, underscoring that the next phase of compliance will depend as much on workable accounting and reporting infrastructure as on the legislative frameworks themselves.

Full Report

Why Traditional Accounting Systems Fail to Scale for Web3 Transaction Compliance

The first session examined why traditional accounting and ERP systems cannot efficiently process Web3 transactions on a transaction-by-transaction basis, and why this has become a material barrier to institutional adoption of digital assets. Participants discussed how short block times, smart contracts, and DeFi processes can generate between 50,000 and 200,000 accounting lines per year for a single active user, the case for a dedicated upstream system that aggregates and translates blockchain transactions into traditional accounting logic while preserving a revision-safe audit trail, and the disproportionate burden the current approach places on smaller businesses. The session also explored the deeper challenge of normalizing diverse DeFi strategies for correct tax treatment, the absence of international accounting standards for crypto-assets, and the role the industry could play in shaping them.

Information Asymmetries between Users and Tax Authorities in DAC8 Reporting

The second session addressed the structural information asymmetry under DAC8 reporting: the imbalance between the extensive crypto-transaction data transmitted automatically to tax authorities and the limited transparency available to affected users. Participants confirmed the asymmetry, drawing on comparable experience under DAC2/CRS where authorities issued assessments based on gross proceeds rather than realized gains, and stressed that DAC8 is a transparency framework, not a taxation norm. While the group did not reach consensus on proactively distributing full reports to all users, it agreed clearly that users must be able to obtain meaningful transparency where needed, through transaction-level drill-down on request and generic explanatory reports describing how figures are aggregated, valued, and classified.

Extensive Reporting on Crypto Transactions and the Challenge of Correct Classification of Digital Assets

The third session addressed two interlocking challenges in operationalizing DAC8/CARF reporting: the complexity of fiat conversion and valuation across reportable transactions, and the difficulty of correctly classifying digital assets to determine which reporting regime applies. Participants discussed the lack of clarity around acceptable conversion rates, the consequential and jurisdiction-specific question of whether an asset is reportable under CRS or CARF, and the risk of authorities issuing assessments based on gross amounts rather than realized gains. The discussion also examined the structural underrepresentation of crypto-native firms in international standard-setting, and concluded candidly that, absent a globally unified legal and tax framework, there is no complete solution to the classification challenge, with the realistic path lying in pragmatic simplifications, continuity principles, and stronger industry coordination.

Call to Actions

Adopt a standardized upstream aggregation layer at EU level that aggregates Web3 transactions into transaction-type-specific summary bookings while retaining full transaction-level data and a revision-safe audit trail, keeping compliant bookkeeping viable for businesses of all sizes.
Build a shared, jurisdiction-aware transaction mapping library that maps standard Web3 transaction types to their accounting and tax classifications, updated continuously as new DeFi strategies emerge.
Engage the IFRS Foundation on crypto-asset accounting standards, prioritizing consistent treatment of stablecoins and EMTs across IFRS categories and a continuity principle protecting justified, good-faith classifications from retroactive challenge.

Call to Actions

Develop generic DAC8 explanatory reports across CASPs, explaining the aggregation methodologies, valuation logic, classification approaches, and reporting assumptions applied, drawing on shared industry best practices.
Ensure transaction-level drill-down capabilities on request, allowing users to reconstruct how aggregated DAC8 values were built from individual transactions, valuations, wallet classifications, and transfers.
Promote operational transparency beyond GDPR rights, ensuring users receive understandable and practically useful information and that DAC8's character as a transparency framework, not a taxation norm, is clearly communicated to tax authorities.

Call to Actions

Permit standardized conversion and valuation simplifications, allowing CASPs to rely on defined, publicly available conversion rates or daily average rates to reduce operational burden and divergent interpretation.
Pursue pragmatic classification support while acknowledging its limits, recognizing that no shared resource can bind regulators or override jurisdiction-specific tax treatment, paired with a continuity principle protecting good-faith classifications from retroactive challenge.
Clarify the evidentiary status of reports and ensure recognition of corrections, so that reported figures are understood to indicate crypto activity rather than taxable gain, and correction reports are recognized across borders.
Strengthen crypto-native representation in international standard-setting, ensuring OECD and other working groups reflect the operational realities of crypto-native providers and not only the priorities of traditional financial institutions.