The regulatory sandbox is a type of legislative regime, enabling test runs of initiatives whose implementation is made difficult or even impossible due to regulatory barriers. A number of leading countries are already using regulatory sandboxes to develop the optimal regulatory environment for the digital economy in the shortest amount of time something that is impossible using conventional measures. Sandboxes are an effective response to both rapidly developing technologies and solutions, and to lack of clarity when it comes to regulating innovations without having analysed the market behaviour of the proposed product or service. Currently, regulatory sandboxes can be focused on a single economic sector (e.g. fintech sandboxes) or a number of industries in the digital economy, which is known as a universal regulatory sandbox. How do regulatory sandboxes currently function? What are the prospects for this type of legal experiment?