Time-Domain Integral Equations discretized by the Time-Domain Boundary Element Methods are a key technology when dealing with simulation scenarios including wideband devices and non-linearities. The discretization in time of these integral equations can be obtained by a space-time Galerkin approach or by leveraging on a convolution quadrature (CQ) strategy based on Implicit Runge–Kutta methods. The latter will be the focus of this chapter. This contribution will first review the key elements of the CQ approach by delineating the discretization spaces, the strategies for the computation of the linear system matrices, and the associated Marching-on-in-time solutions. Then this work will turn to implementation-related details including the problem of the optimal choice of the modeling parameters. Ultimately, regularization and preconditioning strategies as well as the application of CQ approaches to the main equations of interest in electromagnetics will be discussed. Numerical results will corroborate the treatment showing the practical relevancy of the presented techniques.