The applicability of the Animal Welfare Indicators (AWIN) protocol for sheep on farms in Northern Germany (Schleswig-Holstein) is assessed. Feasible, reliable and valid tools for the on-farm evaluation of the welfare state are needed as the societal interest in the well-being of farm animals has increased. Furthermore, national law demands a regular on-farm self-assessment by animal-based indicators. The AWIN protocol for sheep is based on animal welfare indicators specifically designed for sheep farming. To evaluate the applicability, feasibility and consistency over time, six different farms were evaluated in two successive visits at an interval of a maximum of two weeks, during which the evaluation sheets of the AWIN protocol were applied. In addition to assessing the applicability and effort, the results of the first and second visit of the farms were determined using a combination of reliability (intraclass correlation coefficient (ICC), Spearman rank correlation coefficient (RS)) and agreement parameters (Smallest Detectable Change (SDC), Limits of Agreement (LoA)). The results of this work reveal that some indicators of the AWIN protocol are very well suited to measure animal welfare (e.g. lameness and body condition score (RS: 0.88–1; ICC: 0.74–1; SDC: 0–0.06; LoA: < 0.08)). They show good feasibility and consistency over time. However, also indicators that cannot fully meet these requirements are identified (e.g. mucosa colour and ocular discharge). These indicators must be revised and adapted accordingly in the future. In conclusion, the AWIN Protocol for sheep is an extensively designed evaluation system that is suitable for recording animal welfare. It can be used in sheep farming for internal control. However, the time required and the necessary in-depth specialist knowledge regarding the application should not be neglected.