How does the tax office learn of my cryptocurrency gains, particularly where I only trade on foreign exchanges?
It is a widespread but dangerous misconception to believe that transactions on foreign cryptocurrency exchanges are beyond the reach of the German tax authorities. The tax investigation service routinely uses the instrument of the so-called collective information request pursuant to Section 93(1a) AO to obtain and evaluate user data and transaction histories from trading platforms on a large scale. The Tax Court of Cologne has expressly confirmed that the tax authorities are both entitled and technically capable of securing sufficient control material from these platforms. At the international level, frameworks such as the OECD's Crypto-Asset Reporting Framework (CARF) are playing an increasingly important role in automating the international exchange of tax-relevant crypto transaction data.

Are cryptocurrencies genuine economic assets that the tax office is entitled to tax?
Yes — the legal classification has now been resolved beyond doubt by the highest instance. The Federal Fiscal Court held in its landmark judgment — ref. IX R 3/22 — that virtual currencies such as Bitcoin, Ethereum and Monero qualify as "other economic assets" within the meaning of Section 23(1) sentence 1 no. 2 of the Income Tax Act (EStG). The judges held that crypto-assets constitute objectively valuable and independently assessable positions with a determinable market price on trading platforms. Where these assets are sold at a profit or exchanged for other cryptocurrencies within the one-year speculation period, the gains are fully subject to income tax. Anyone who conceals these gains in their tax return commits criminal tax evasion.

Does the argument of a "structural enforcement deficit" offer a way out in tax criminal proceedings?
No — this line of argument no longer succeeds before the courts. In the past, accused persons frequently argued that taxation was unconstitutional because the state was in any event unable to monitor anonymous trading comprehensively. However, the Federal Fiscal Court has clearly rejected this argument, finding that no normative enforcement deficit exists in respect of the recording of disposal transactions involving crypto tokens. Any gaps in the identification of taxpayers result merely from practical difficulties of official oversight, not from legislation that is deliberately and contradictorily designed. A defense in tax criminal proceedings must therefore be built on technical reconstruction — not on the general hope of unconstitutionality.

What happens if I can no longer prove my trades because an exchange was hacked or has become insolvent?
Missing records and data losses — for example through the collapse of an exchange or a hacking attack — almost invariably operate to the detriment of the taxpayer in tax law. In a case before the Tax Court of Baden-Württemberg — ref. 5 K 1996/19 — in which the claimant asserted data losses arising from a hacking attack on the exchange "Bitgrail," the court applied a strict standard. The tax cooperation and record-keeping obligations under Section 90 AO require users to secure transaction data promptly, as cryptocurrency exchanges frequently retain data for only a few months. Where acquisition costs and dates cannot be demonstrated beyond doubt, the tax office is entitled to estimate the basis of taxation pursuant to Section 162 AO. Such official estimates almost invariably fall significantly to the detriment of the accused and artificially inflate the tax damage alleged in criminal proceedings.

When does cryptocurrency activity give rise to an allegation of trade tax evasion?
The risk of trade tax evasion is particularly high in connection with activities beyond straightforward trading. According to the authoritative guidance of the Federal Ministry of Finance dated 10 May 2022, cryptocurrency mining — such as under the proof-of-work protocol — generally constitutes a commercial activity giving rise to trade tax liability where certain thresholds are exceeded. The same may apply to the operation of a masternode, since this involves performing a critical function within the blockchain network in exchange for a reward. Where such income is concealed from the tax office, the tax investigation service investigates not only for evaded income tax but adds the further offence of trade tax evasion to the allegations.

Can the state seize my wallets or freeze assets in cryptocurrency investigation proceedings?
Yes — law enforcement authorities intervene massively in the property rights of accused persons where tax evasion is suspected. As soon as suspicion arises, public prosecutors and tax investigation services use the criminal procedural asset arrest pursuant to Sections 111b et seq. StPO in conjunction with the rules on confiscation of criminal proceeds under Sections 73 et seq. StGB to secure crypto-assets or conventional bank balances. In legal practice, however, it is evident that such freezing orders are in some cases issued by the courts erroneously, in an outcome-driven manner, or without adequate examination of the substantive elements of the offence. Against these often financially devastating seizures of private keys or exchange accounts, we as specialist attorneys pursue every available avenue of criminal procedural challenge.