Crypto Tax: German Investors Must Export Data Before Exchange Closes

German investors with accounts at crypto exchanges that are winding down face a September deadline to download their full transaction history. The reason is straightforward: without the raw data, they cannot prove to the tax office when they bought a coin or what they paid. Once the account closes, the trading record is typically no longer retrievable, and the burden of proof sits with the investor.

Several trading venues have set cut-off dates before the end of September. After those dates, balances may be sold off and accounts closed. The notices from the providers govern how long funds can be withdrawn. None of them guarantee continued access to trading records.

The tax risk follows from German law. Under Section 23 of the Income Tax Act, gains from crypto disposals within one year of acquisition are taxable. To show that a sale fell outside that period, the investor needs the acquisition date. To calculate the gain, they need the acquisition cost in euros. To prove they stayed below the €1,000 exemption threshold, they need every transaction of the calendar year, not only the large ones. The exemption is a threshold, not an allowance: if the total gain exceeds €1,000, the entire amount becomes taxable.

A crypto exchange does not issue an annual tax certificate or withhold capital gains tax. Once the business relationship ends, it owes nothing beyond the statutory minimum. The trading record disappears unless the investor exported it beforehand.

The raw transaction history – a CSV file with timestamps, trading pairs, quantities, prices, and fees – is the most valuable piece of data. A finished tax report can be reconstructed from it. The reverse does not work. Account statements showing deposits and withdrawals in euros do not capture which coins were bought when or at what price.

German tax law contains a provision that worsens the position of someone who fails to secure their data. Section 90 of the Fiscal Code requires taxpayers to cooperate in establishing facts. For matters abroad, subsection 2 demands that every legal and factual possibility be exhausted to clarify the facts. The clause at the end states that nobody can invoke a lack of means to clarify matters if they could have secured those means by arranging their own affairs properly. An investor who knew the account would close and did not pull the export is in a worse position than someone whose exchange collapsed without warning.

If the tax office cannot determine the tax base, it may estimate it under Section 162 of the Fiscal Code. An estimate rarely works in the taxpayer's favor. In the worst case, an acquisition price of zero is assumed, making the entire disposal proceeds taxable.