Note: This article is based on research of public sources (statutes, official publications, professional literature) and professional experience. It provides a general overview but does not claim to be exhaustive and is not a substitute for individual advice from a tax advisory firm or specialist law firm for tax law. TX-Partner assumes no liability for the accuracy, timeliness, or completeness of this information.
Key Takeaways
- ✓ A tax authority inquiry is a routine information request — not an accusation or criminal proceeding
- ✓ Currently the most common triggers are collective requests and follow-up questions on the tax return
- ✓ Required documents include tax tool reports, CSV exports from all exchanges, wallet addresses, and bank statements
- ✓ Typical deadline is 2–4 weeks; a written extension request is usually granted without issue
- ✓ Ignoring the inquiry risks an estimation by the tax authority, late payment surcharges, and criminal proceedings
An official letter from the tax authority asking about your crypto transactions. That's unusual at first. But also no reason to panic. Let's look at what this means and how to handle it.
01 What Does a Tax Authority Information Request Mean?
A supplementary request (in Austria) or information request (in Germany) is a normal inquiry. The tax authority wants more information about a specific matter. In your case: about your crypto activities.
Important to understand: This is not an accusation and not a criminal proceeding. It's an audit. The tax authority has received data (for example through DAC8 reports) and wants to compare it with your statements. Or they simply lack information.
02 Why Is the Tax Authority Asking About Your Crypto?
Crypto inquiries from the tax authority typically have specific triggers. Here are the most common ones:
Typical Triggers:
DAC8 Reports
Since January 2026, crypto exchanges automatically report to tax authorities. If the reported data doesn't match your tax return, inquiries arise.
Collective Information Requests
The tax authority requested user data from exchanges like Bitcoin.de (for 2019-2022). If you were active there, your name could be on the list.
Routine Audit
Sometimes it's simply random sampling or hints in bank statements (e.g., transfers to crypto exchanges).
None of these reasons is inherently problematic. It's about establishing transparency. You can do that.
03 DAC8: The Facts
DAC8 (Directive on Administrative Cooperation) is the EU directive that extends automatic information exchange to crypto assets. Here are the verified facts:
DAC8 Timeline:
October 17, 2023
DAC8 adopted by the EU Council
January 1, 2026
Reporting obligation takes effect - crypto service providers begin data collection
September 30, 2027
First reports to tax authorities (EU-wide)
What gets reported?
The reporting obligation is broad-based. Crypto service providers report:
- Identification data - Name, address, tax ID, date of birth
- Transaction data - Every purchase, sale, exchange with date and value
- Wallet addresses - All addresses used
- Year-end balances - Value of held crypto assets as of December 31
Germany: KStTG
Germany implemented DAC8 with the Crypto Assets Tax Transparency Act (KStTG), passed on November 6, 2025. A special feature: The reporting deadline in Germany is July 31, 2027 - two months before the EU deadline.
Penalties for Violations
Crypto service providers who don't comply with their reporting obligation risk fines of up to 50,000 EUR per case. This primarily affects the platforms - but the reported data will be compared with tax returns. Discrepancies lead to inquiries.
Sources: EU Commission, German Bundestag
04 Collective Information Requests: The Bitcoin.de Case
Besides DAC8, there's another reason for tax authority inquiries: collective information requests. The best-known example is Bitcoin.de.
Bitcoin.de Collective Information Requests:
Period 1: 2015-2017
First collective information request to Bitcoin.de
Period 2: 2019-2022
Second collective information request - approx. 4,000 accounts affected (from 50,000 EUR annual turnover)
September 25, 2025
Second data package handed over to tax administration
The initiator was the State Office for Combating Financial Crime NRW (LBF NRW). The collected data is distributed nationwide to the responsible tax authorities. This means: If you live in Bavaria but data was collected in NRW, you'll get mail from the Bavarian tax authority.
Source: Tax Administration NRW
05 Austria vs. Germany: The Differences
The terms and legal bases differ between countries. Here's an overview:
| Aspect | Austria | Germany |
|---|---|---|
| Term | Supplementary Request | Information Request |
| Legal Basis | BAO §143 | AO §93 and §208 |
| Typical Deadline | 2-4 weeks | Specified in letter |
| Statute of Limitations (normal) | 5 years | 4 years (7 with negligent shortfall) |
| Statute of Limitations (intent) | 10 years | 10 years |
The processes are similar, but the legal details differ. For specific handling, coordination with a tax advisor who knows the respective country's law is always recommended. For the full tax framework for Austria, see the Crypto Tax Austria 2026 guide. For Germany (holding period, FIFO, Anlage SO), see the Crypto Tax Germany 2026 guide.
Sources: Austrian Federal Ministry of Finance, German Tax Code
06 What happens if you don't respond?
Ignoring is not a strategy. Here are the possible consequences:
Estimation by the Tax Authority
If you don't provide documents, the tax authority estimates. These estimations typically don't fall in your favor.
Late Payment Surcharges (Germany)
0.25% of assessed tax per month, minimum 25 EUR per started month.
Late Payment Interest (Germany)
0.15% per month = 1.8% per year on the back payment amount.
Criminal Consequences
In case of intent: Tax evasion under §370 AO. The lines between negligence and intent are fluid.
Sources: German Tax Code (§162, §370 AO), Austrian Federal Ministry of Finance
Voluntary Disclosure as an Option
If you realize that mistakes were made in the past, voluntary disclosure can be an option. Important: Voluntary disclosure must occur in time - that is, before the tax authority becomes aware of the discrepancies on its own. The inquiry itself may have already passed this point.
What a complete voluntary disclosure requires, what the most common data gaps are, and why 2026 is the decisive window: Crypto Voluntary Disclosure 2026: What You Need to Know Now.
07 What is typically requested?
The requirements are stated in the letter. From 500+ cases of experience, the following are frequently mentioned:
- Tax reports from crypto tax tools - Blockpit, CoinTracking, Koinly or comparable
- CSV exports - Complete transaction histories from exchanges and wallets
- Wallet addresses - List of all addresses used
- Exchange statements - Official annual statements from platforms
- API credentials - In rare cases for verification
The good thing about this: The requirements are clear. You know exactly what you should deliver. The only question is: Do you have it?
Checklist: Documents you need for your response
Complete Tax Report
From Blockpit or CoinTracking, without warnings, for all requested tax years
CSV Exports from All Exchanges
Transaction histories from every platform used (Binance, Kraken, Coinbase, etc.)
List of All Wallet Addresses
Hardware wallets, hot wallets (e.g. MetaMask, Rabby, Phantom), DeFi wallets, with chain assignment
Exchange Annual Statements
Official statements from platforms (if available)
Bank Statements with Crypto Transactions
Bank receipts for deposits to and withdrawals from crypto exchanges
Typical Deadlines and Procedures: Austria vs. Germany
08 How to Respond to a Tax Authority Crypto Inquiry
A supplementary request is an information inquiry - not a criminal proceeding. You have time to respond, and the process is clearly structured:
1. Stay calm. A supplementary request is standard. Tax authorities send these routinely, especially since DAC8.
2. Check and note the deadline. Typically 2-4 weeks. If you need more time, request a deadline extension in writing. This is typically unproblematic.
3. Inform your tax advisor. For tax assessment and final submission, you should involve a tax advisor.
4. Check tax report for errors. Open your Blockpit or CoinTracking report. Are there warnings? "Short (Warning)"? "Missing history"? Negative balances? These errors should be corrected before the report is submitted.
5. Have crypto accounting corrected. If the report shows errors, professional help with data cleaning can be sensible. TX-Partner prepares crypto accounting so that the report is audit-ready.
6. Respond in writing. Always in writing, never by phone. Document everything. The tax advisor handles the final submission to the tax authority.
09 Documentation makes the difference
The inquiry itself is rarely the problem. The challenge arises when your tax report doesn't show what it should.
You should know these indicators in tax reports:
- • Negative balances in CoinTracking
- • Divergent balance in Blockpit
- • "Short (Warning)" for sales without purchase history
- • Error messages in the tax report with cost basis 0 EUR
- • "Missing history" tags
These indicators point to gaps in transaction history. A clean report without such warnings facilitates all communication.
Submitting a report with negative balances or cost basis 0 EUR essentially hands the tax authority the next prompt for an inquiry. The result is a discussion about why the documentation has gaps — and an estimation that rarely lands in the taxpayer's favour. The clean route is the other way around: correct the documentation before submission, so the report leaves no open flanks.
10 Preparation instead of reaction
The best time to get crypto accounting in order is before the letter arrives. The second-best is now. Ideally the documentation is already cleanly prepared, then the inquiry is a formality: export report, submit, done.
In practice, the inquiry often arrives at the exact moment it becomes clear that wallets are missing, DeFi isn't fully captured, the report shows warnings. That's where TX-Partner steps in: not as tax advisor, but at the data root. TX-Partner identifies the gaps, reconstructs missing transactions, classifies DeFi activity correctly, and brings the report to a state your tax advisor and the tax authority can work with.
If it's unclear whether your crypto accounting holds up against the inquiry, Robert or Johannes will look at it in the free Data Check and give an honest assessment of what you can prepare yourself and where professional rework makes the difference. 30 minutes, no commitment.
Sources & References
Co-Founder & Documentation Specialist
Robert Thorn is Co-Founder of TX-Partner. Brings experience from over 500 documented crypto portfolios, from simple Bitcoin trading to six-figure DeFi setups across multiple chains and years. Closes the gap between raw data and clean documentation for tax and banks.
