Note: The information in this article provides a general overview and does not claim to be exhaustive. It is not a substitute for individual advice from a tax advisor or tax law specialist. TX-Partner assumes no liability for the accuracy, timeliness, or completeness of this information.
At a glance
- ✓ Criminal immunity only when complete: AT (§ 29 FinStrG) and DE (§ 371 AO)
- ✓ DAC8 active since January 2026 — first automatic reports to authorities: September 2027
- ✓ NRW collective inquiry: approx. 4,000 Bitcoin.de users already affected
- ✓ Every voluntary disclosure begins with complete data preparation — that is the nature of the process
- ✓ Data preparation is step one — before going to the tax advisor
You are considering a voluntary disclosure. Perhaps your tax advisor raised the topic, or you noticed yourself that past tax returns were incomplete. The window for proactive action is real. And in 2026, it is closing faster than many realize.
Many who contact us have been carrying this for years. Their first active crypto year was 2017/18 or 2020/21. Back then, tax rules were unclear, tools were immature, and documentation was barely on anyone's radar. What was an open question then has become a real burden today.
With each year without a resolution, the uncertainty grows. Many are no longer sure exactly whether — or how much — was actually taxable. The trades are years in the past, the rules were interpreted differently at the time, and the assumption that "it probably wasn't that much" sits stubbornly. Bringing in a tax advisor absolutely makes sense in this situation. But before it is clear what was documented and what of that is taxable, no tax advisory firm can assess what makes sense next. Documentation is step one.
What many underestimate: a voluntary disclosure only provides criminal immunity when it is complete. And that is precisely where the biggest practical risk lies.
01 What Is a Crypto Voluntary Disclosure?
A criminal-immunity voluntary disclosure gives you the opportunity to declare previously unreported crypto gains and pay the outstanding taxes — without risking criminal consequences. In Austria this is governed by § 29 FinStrG, in Germany by § 371 AO.
The decisive principle in both countries is the same: the voluntary disclosure must be complete. It must cover all affected years, all relevant transactions, and all exchanges and wallets involved. Back payment within the set deadlines is mandatory.
What happens with an incomplete voluntary disclosure: it does not provide criminal immunity. You have disclosed yourself without the protection you were seeking. What this means in concrete terms must be assessed by a tax advisory firm for the specific case.
Who does this affect?
A voluntary disclosure is relevant if you reported crypto gains in past tax returns not at all or incompletely. Typical situations:
- ✓ Active years 2017–2021 with trades across multiple exchanges — without complete tax reporting
- ✓ DeFi activities (staking, liquidity pools, yield farming) that never appeared in a tax report
- ✓ Portfolio on exchanges that share data with tax authorities (Bitcoin.de, Kraken, Coinbase EU)
- ✓ Already received a letter from the tax authority, but no formal proceedings initiated
02 Why Is 2026 the Decisive Year for Crypto Voluntary Disclosures?
DAC8 has been active since January 2026. Crypto service providers across the EU have begun structured data collection. Under EU Directive 2023/2226, the first complete automatic transmission of this data to tax authorities is scheduled for September 2027 — for data collected from the 2026 calendar year.
This means: until September 2027, tax authorities are still working without a comprehensive, automated dataset of your crypto activities. Anyone who wants to act proactively has more room to maneuver now than after the first automatic data exchange.
The DAC8 Window 2026/2027:
January 2026
DAC8 active — crypto exchanges begin structured data collection (transactions, identities, balances)
Now (2026)
Proactive action possible — tax authorities do not yet have an automated completeness check
September 2027
First automatic exchange reports to tax authorities EU-wide — the window is closing
Another concrete warning signal has already appeared: the North Rhine-Westphalia State Office Against Financial Crime (LfF NRW) initiated a collective inquiry against Bitcoin.de. Around 4,000 users with annual turnover from EUR 50,000 are affected; the data was distributed to tax offices nationwide. What this means for you and how to respond correctly is explained in this article.
The signal is clear: investigative measures are already underway. DAC8 scales that to a new dimension from 2027.
03 Austria and Germany: The Key Differences
The basic principle is the same in both countries. The details differ.
| Austria § 29 FinStrG |
Germany § 371 AO |
|
|---|---|---|
| Criminal Immunity | Before an audit starts or before the offense is discovered | Before criminal proceedings are initiated and before the offense is discovered |
| Requirement | Full disclosure of all affected taxes and periods | Full correction of all incorrect statements |
| Payment | Back payment incl. late interest within the set deadline | Back payment incl. interest within the deadline |
| Surcharge | With intent: from 10 % of the evaded amount | From EUR 25,000/year: criminal surcharge 10–20 % required |
The specific tax and criminal law assessment of the case belongs in the hands of a tax advisory firm or tax law specialist firm. TX-Partner prepares the crypto documentation on which that assessment is based.
04 What a Voluntary Disclosure Must Include
A criminal-immunity voluntary disclosure is not an informal confession. It is a structured document with clearly defined components. What it must contain depends on your specific situation, but always follows the same basic structure.
- Complete transaction history of all exchanges, wallets, and protocols over the entire affected period
- Tax calculations per assessment year based on the prepared documentation
- Tax assessment and any applicable optimizations by the tax advisory firm
- Amended tax returns and back payment incl. late interest within the set deadline
Components in Detail:
Complete Transaction History
All purchases, sales, swap transactions, staking income, and DeFi interactions over the entire affected period. The transaction history is itself the evidence — structured and presented in writing so that the authority receives a complete picture.
Tax Calculations per Assessment Year
For each affected year, a traceable calculation of gains and the resulting tax liability — prepared via a crypto tax tool based on the prepared documentation.
Tax Assessment by the Tax Advisor
The evaluation, qualification of transactions, and where applicable tax optimizations are the responsibility of the tax advisory firm. Particularly relevant when multiple tax years or complex DeFi activities are involved.
Amended Tax Returns and Back Payment
The tax advisory firm prepares the amended returns for all affected years. Back payment of the tax liability incl. late interest is made within the set deadline.
The part that regularly causes problems with crypto investors: the complete transaction history. A tax calculation is only as complete as the data it is based on. Crypto tax tools only produce correct results when all data is present. That is precisely the area where TX-Partner works.
05 Why Incomplete Data Is the Biggest Risk in a Voluntary Disclosure
Robert and Johannes know this from their earlier work in law firms: every voluntary disclosure case began with data preparation. This is not due to negligence. Documentation becomes a bigger challenge with each passing year. What seemed manageable in 2018 grew — across multiple exchanges, DeFi positions, NFT activities from 2021/22, and forgotten wallets — into a task that keeps getting postponed. When the voluntary disclosure is finally on the table, what is missing first is the complete transaction history. The most common gaps:
- Old or closed exchanges — the data is often still retrievable, but access is gone or the account has long been deactivated
- DeFi protocols — swaps, liquidity pools, staking rewards from 2020–2022 are missing from almost every standard export
- Multiple wallets — one wallet was forgotten, another had few transactions and was therefore ignored
- Early years (2017–2019) — CSV exports no longer match current tools, exchanges have changed their data formats
From the field:
A client comes prepared for a voluntary disclosure: period 2020–2024, Blockpit import already completed. During the documentation check, TX-Partner identifies over 1,200 open issues. The tax reports showed a discrepancy in the low five-figure range, because errors had been systematically calculated to the client's disadvantage. Only after complete preparation was there a reliable foundation for the voluntary disclosure.
A voluntary disclosure with an incomplete data foundation puts its own criminal immunity at risk. What this means in the specific case is a legal question that a tax advisory firm or specialist firm must assess. What TX-Partner can assess: whether the data foundation is complete before the voluntary disclosure is submitted.
06 What "Complete" Means for a Crypto Voluntary Disclosure
Complete does not mean "as complete as I can manage." Complete means: all relevant transactions, traceable without gaps, over the entire affected period.
What complete crypto documentation for a voluntary disclosure covers:
All Exchanges
Active, inactive, and closed platforms. Even platforms with few transactions count.
All Wallet Addresses
Verifiable and reconstructable on-chain. Hardware wallets, software wallets, DeFi wallets.
All Affected Years
Not just the years with high gains. The voluntary disclosure must cover all relevant assessment periods.
All Transaction Types
Trades, staking rewards, airdrops, DeFi interactions, bridging, NFT sales — every taxable event.
The same requirements apply to proof of funds for banks: complete, traceable, all sources documented. Anyone preparing documentation for a voluntary disclosure has the foundation for both use cases.
07 What TX-Partner Handles, and What It Does Not
TX-Partner prepares the crypto documentation that tax advisors and tax law specialists need for a complete voluntary disclosure. It starts with the question of what is actually available. It ends with a complete, export-ready data foundation.
Concretely this means:
- Consolidating the complete transaction history of all exchanges and wallets
- Reconstructing missing data — closed exchanges, old wallets, DeFi protocols on-chain
- Classifying all transaction types according to the TX Documentation Standard
- Export-ready preparation for crypto tax tools and tax advisors
TX-Partner does not submit voluntary disclosures and does not provide tax advice. TX-Partner ensures that the data is correct — the data the voluntary disclosure is built on. No patch over gaps, but solid documentation.
What is often just as important as the data: experience with situations like this. Robert and Johannes have prepared crypto portfolios in law firms and with TX-Partner where the transaction history went back to 2014 — some to 2017, others only from 2020. What is almost always the same: the data is distributed, incomplete, and spread across many platforms. We know what a tax advisory firm actually needs to file with confidence.
What we experience again and again: the first step is not the hardest in terms of content. It is the emotional one. The decision that it needs to be dealt with now. The clarity that emerges after complete preparation is for many clients the decisive moment — not because the tax situation is resolved, but because the picture is finally complete. Because a diffuse burden becomes a concrete task list.
TX-Partner's first step is the free documentation check: a look at your situation, the open questions, and what makes sense next. More about TX-Partner's services here.
Sources & References
Co-Founder & Documentation Specialist
Robert Thorn is Co-Founder of TX-Partner, specializing in complex crypto documentation for tax advisors and private investors in Austria and Germany. 500+ cases, from DeFi to voluntary disclosure.
