In order to ensure machining stability, it is essential to properly determine the dynamic properties of machine tool–workpiece system. Experimental modal analysis provides good results; however, due to high time consumption, in some cases, its use is not practically justified. Then, a receptance coupling method can be used, that allows for the synthesis of the experimental models of the machine tool components and analytical models of the workpiece. However, a significant disadvantage of this method is the need for the experimental identification of the rotational degrees-of-freedom, fully defining dynamic properties of the spindle. This paper presents an improved method based on inverse receptance coupling, which enables effective identification of the spindle dynamics with the properties of the joint. Then, a measurement procedure and results of the experimental validation are presented.