The key point of isogeometric analysis is the usage of a common geometry definition for design and analysis [1]. Thereby, Non-Uniform Rational B-splines (NURBS) within the frame of the finite element method is the most common choice in structural mechanics. NURBS are a versatile tool for geometric modeling, and in order to define complex geometric structures, a multitude of tensor-product NURBS patches is required. While the coupling in Computer-Aided design software is rather visual, we need a proper mechanical coupling of the patches in the finite element method. A large variety of coupling methods has been proposed over the last years. In particular, the dual mortar method has been shown to yield very efficient computations [2]. In a recent paper we provided an isogeometric mortar method with mathematically proven optimal convergence of the stress errors over the entire domain [3]. By using dual basis functions, which have support only on one interface, interrelations between different interfaces are avoided. In our current contribution, we show how to combine both aforementioned approaches to arrive at a method with non-interrelated interfaces, local support on the interfaces and optimal convergence rates. Numerical examples show the optimal convergence behavior both for simple and complex discretizations. REFERENCES [1] T.J.R. Hughes, J.A. Cottrell and Y. Bazilevs, Isogeometric analysis: CAD, finite elements, NURBS, exact geometry and mesh refinement, Computer Methods in Applied Mechanics and Engineering 194 (2005): 4135-4195. [2] W. Dornisch, J. Stöckler, R. Müller, Dual and approximate dual basis functions for B-splines and NURBS–Comparison and application for an efficient coupling of patches with the isogeometric mortar method, Computer Methods in Applied Mechanics and Engineering 316 (2017): 449-496. [3] W. Dornisch, J. Stöckler, An isogeometric mortar method for the coupling of multiple NURBS domains with optimal convergence rates, Numerische Mathematik 149 (4) (2021): 871-931.