Financial Forensics
Bitcoin expert in tax criminal law
Crypto tax reports for criminal proceedings – FIFO-compliant and legally sound
If the tax office is investigating your client regarding crypto holdings: We provide you with a legally sound crypto valuation report – wallet identification, complete transaction reconstruction, FIFO calculation according to the German Federal Ministry of Finance (BMF) guidelines. Initial assessment within 24 hours.
- Specializing in crypto expert opinions in tax criminal law – not „a tax advisor who also knows crypto“
- FIFO methodology according to current BMF guidelines, clearly documented and defensible in court.
- Direct line to the management Lydia Bonhard-Lüdtke and David Lüdtke
Request for crypto expert opinion in criminal proceedings
Please briefly describe the situation to us – the current status of the proceedings, the investigating authority, and the available data. We will contact you within 24 hours with an initial expert assessment and cost estimate.
Why tax defense lawyers work with financial forensics
FIFO-compliant calculation
According to the BMF letter, with a comprehensible methodology and reproducible data basis.
Wallet and exchange forensics
Complete reconstruction of holdings and transactions over years, even with fragmentary data.
Legally admissible expert opinions
Methodology chapter, source hashes, tool versions; expert testimony in the main hearing upon request.
Strict confidentiality
NDA upon request, encrypted data transfer, engagement via the law firm with protection through attorney-client privilege.
24-hour feedback
Initial review of the facts within one working day, transparent cost estimate.
Management as contact person
Lydia Bonhard-Lüdtke and David Lüdtke handle every project personally – no back-and-forth between clerks.
This is how a legally sound crypto tax assessment is created.
1
Initial consultation and data collection
You describe the status of the proceedings, the alleged offense, and available data sources (exchange exports, wallet addresses, tax documents, seizure data). We assess the data and define the scope of the expert opinion. Initial assessment within 24 hours.
2
Wallet analysis and FIFO calculation
We consolidate exchange data, identify associated wallets, reconstruct on-chain transactions, and calculate holdings, inflows and outflows, capital gains, and holding periods using FIFO – in accordance with the current BMF letter on the income tax treatment of crypto assets.
3
Expert opinions and defense support
You will receive a structured report detailing the methodology, data basis, calculation logic, and results – including sensitivity analyses for disputed assumptions (e.g., hard forks, staking, NFTs). Upon request, statements for tax investigations and expert testimony are also available.
What our crypto tax assessment can do
Wallet identification
Mapping of addresses to people and exchanges, cluster analysis, heuristics for evidence preservation.
Full transaction reconstruction
On-chain analysis across all relevant chains (Bitcoin, Ethereum, Layer-2, other major chains).
FIFO calculation according to the BMF letter
Acquisition costs, sales proceeds, holding periods, capital gains; reproducible and verifiable.
Special cases documented
Hard Forks, Airdrops, Staking, Lending, NFTs, Liquidity Pools, DeFi – each with its own valuation logic.
Counter-report
Statement on calculations by the tax investigation, detection of methodological errors, alternative FIFO paths in case of data gaps.
Plausibility check of client information
A realistic assessment of what can be carried in a defense and where the risks lie.
Expert opinion
Appearance at the main hearing, explanation of the methodology to the court and the public prosecutor's office.
Basis for self-reporting
Reliable calculation as the basis for an effective voluntary disclosure – according to §371 AO.
Our typical clients
Tax defense lawyer
Main target group: Commissioning via the law firm, protection through attorney-client privilege, clear division of tasks.
Tax advisor in criminal proceedings
When the tax advisor continues to support the client and needs an expert opinion as a basis for discussion.
Economic criminal defense lawyer
In proceedings relating to money laundering, fraud or insolvency offenses involving crypto.
Defense attorneys in self-reporting situations
Reliable calculation as a basis for an effective self-disclosure.
We work on the defense side. We handle requests from government agencies separately and only after formal authorization.
The people behind Financial Forensics
Financial forensics is provided by Lydia Bonhard-Lüdtke and David Lüdtke The team is led by [name of lead expert/company representative]. Both bring experience in financial analysis, IT and crypto forensics, and expert witness work. The team is complemented by IT forensic specialists and a network of tax lawyers and experts.
In tax evasion proceedings, reproducibility is crucial: Every figure in the expert opinion must be precisely traceable from the documented data – otherwise, the opinion is vulnerable to challenge in the main trial. Therefore, Lydia Bonhard-Lüdtke and David Lüdtke personally handle every case.
Frequently asked questions about cryptographic reports in criminal proceedings
As soon as the tax investigation authorities present their own calculations, a counter-assessment is almost mandatory. Even in the pre-indictment phase – in cases of threatened voluntary disclosure or during the investigation itself – a reliable expert opinion clarifies the actual tax risk and the available defense options.
FIFO (First-In-First-Out) is the consumption sequence to be applied according to the German Federal Ministry of Finance (BMF) guidelines: Coins acquired first are considered to be sold first. We consistently calculate acquisition costs, holding periods, and capital gains according to FIFO and fully document the calculation method.
Coin tracking tools provide a basis for calculation, but not an expert opinion. In court, the methodological justification, the completeness of the data, the handling of special cases (hard forks, staking, NFTs), and the plausibility of the assumptions are decisive. These steps belong in an expert opinion – not in a tool export.
We prefer to handle cases through the defense attorney's office. This ensures attorney-client privilege and a clear line of communication. We only accept direct instructions from defendants in exceptional cases and after consultation.
We work on an hourly or flat-rate basis. After the initial consultation, you will receive a written estimate of the required effort. Flat rates are possible for clearly defined tasks; for large data volumes and international exchanges, we work with budget ranges and interim reports.
A plausibility check with a manageable amount of data will be available in 2 to 3 weeks. Comprehensive reports covering multiple tax years, multiple wallets, and multiple exchanges require 4 to 8 weeks. We will confirm the exact timeframe after our initial consultation.
This is more the rule than the exception. We work with complete transparency: we document where data gaps exist, provide plausible estimates in favor of or against the client (depending on the assignment), and offer sensitivity analyses for disputed assumptions. This is precisely what a court expects from a reliable expert opinion.
Send inquiry – response within 24 hours
Are you defending against a tax evasion case involving cryptocurrencies or preparing a voluntary disclosure? Briefly describe the status of your case and the available data – we will get back to you within one business day with an initial professional assessment and an estimate of the costs involved. Confidential, free of charge, and without obligation.
Professional financial forensics and OSINT investigations for lawyers, legal professionals and companies.
Subsidiary brand: Crypto Investigation
+49 6057 772 994 86
postfach@finanz-forensik.de
9:00 AM – 8:00 PM
© 2026 Finanz Forensik GmbH. All rights reserved.