The synthesis of sterically demanding 2,6‐bis(2,4,6‐trimethylphenyl)phenyl (Ter)‐stabilized potassium phosphinophosphido dithioformates 1a–b K[TerP(CS 2 )PR 2 ] via conversion of the corresponding potassium phosphinophosphides K[TerP–PR 2 ] (R = i Pr, t Bu) with CS 2 is reported. In solution, the dithioformates 1a–b undergo a migration reaction, resulting in the formation of anionic phosphanylthioketones, K[TerPC(=S)–P(S)R 2 ] ( 2a‐b ), bearing phosphanylthiolate groups. The cocrystallization of compounds 1a and 2…