The regulation of crypto assets and business models based thereon has evolved significantly over the past ten years, both at national and European level. While BaFin, as the competent supervisory authority in Germany, classified bitcoins and comparable crypto assets as units of account and thus as financial instruments shortly after their emergence in 2009, the German legislator followed suit not before 2020 when implementing the 5th Anti Money Laundering Directive and introduced a legal definition of the term crypto asset in the German Banking Act (KWG). Business models with or in relation to crypto assets, such as crypto custody or crypto trading for customers in particular have since been subject to a legal licensing requirement in Germany. Crypto asset service providers must therefore successfully undergo a licensing procedure to obtain a BaFin license before commencing business. Alternatively, in individual cases, cooperation with a financial service provider that has the required BaFin license may be considered.