Transaction costs (TCs) are often claimed to be a key determinant of how policies are actually implemented on the ground and what effect they ultimately deliver on soil quality and functions. Focusing on agriculture-related soil protection policies in Eastern Germany, we analyse data from key informant interviews in two case study areas (Brandenburg and Saxony-Anhalt) in order to provide new evidence that TCs do indeed matter for policy implementation. We systematically map TCs that occur at the policy implementation and operation stages and their drivers. Our data showed that in addition to TCs for ‘information management’ and ‘coordination’, existing frameworks need to be extended to explicitly consider TCs for ‘enforcement’. Results illustrate that there is a broad range of TCs that are due to the complexity of soils and their management, property rights assignment and administrative processes. To some extent TCs in one policy arena can be reduced; however, often they are only superseded in place and time and, moreover, there are trade-offs between different kinds of TCs. The paper emphasizes that every assessment of effective policy implementation requires a specification of TCs and over what time frame they occur.