Selling bitcoin privately is not a special case under German tax law. The same rule applies as for a sale through a crypto exchange: if more than a year sits between purchase and sale, the gain is tax free under Section 23 of the German Income Tax Act. Sell inside the one-year window and the gain becomes taxable as soon as all private disposals in a single calendar year together exceed the threshold of 1,000 euros. Whether the money changes hands as cash across a café table, arrives by SEPA transfer or runs through the escrow of a peer-to-peer marketplace makes no difference to that calculation.