Boron-hydrogen compounds are of increasing importance as electrolytes in solid state batteries, for hydrogen storage and possibly as high temperature super conductors. Solvent based methods are of increasing importance to obtain pure products, for purification of materials and also for the synthesis of novel compounds. In this context, the solubility information of several classes of metal-boron-hydrogen compounds such as borohydrides, closo -decahydridodecaborates, closo -dodecahydridododecaborates, arachno - and nido -hydridoborates in typical solvents is vital. This information is currently dispersed in the literature, hence the need to present a cohesive summary and comparison of these properties. This review collects, analyses and discusses the available data to provide inspiration for the future design of new synthesis routes and the discovery of novel materials.