CARMENES. V: CARMENCITA, M dwarfs in multiple systems Cortés-Contreras, Caballero, Alonso-Floriano, Dorda, Klutsch, López-Santiago, Montes, Morales With the help of CARMENCITA, the CARMENES Cool dwarf Information and daTa Archive, we investigate the membership in double, triple or higher-order systems of almost 1000 of the brightest, latest M dwarfs in the solar neighbourhood. We use data compiled from the literature and measured by us. Angular separations range from a few tenths of arcseconds to several arcminutes, which translate into a very wide interval of projected physical separations. Studying M dwarfs in multiple systems provide information on a wealth of topics, e.g. from dynamical masses, through distance and metallicity, to the formation and evolution of weakly bound systems.