We present a computational framework for the efficient simulation of brittle and ductile fracture in complex shell structures via isogeometric phase-field descriptions. In our approach, the phase field is described as two-dimensional field on the shell’s middle surface. However, the phase-field equations are evaluated at different integration points through the shell thickness, resulting in a non-constant degradation function through the thickness. This allows for a correct description of the fracture behavior under bending and yields a very good match with the results of full 3D simulations. For the application to complex shell structures, we employ a penalty-based patch coupling technique, where C0 and C1 continuity can be imposed for both the structural and the phase field via a single, dimensionless penalty parameter [1]. For the efficient simulation of crack evolution, we perform multi-level adaptive refinement using LR-NURBS. The applicability and accuracy of the method is demonstrated on several benchmark examples with experimental verification, including the full-scale indentation test of stiffened steel panels [2].