Four iodoargentate hybrids, [Eu(DMSO)₈]₂[Ag₂I₅][Ag₅I₈] (1), [Eu(DMSO)₈][Ag₇I₁₀] (2), [Tb(DMSO)₈]₂[Ag₂I₅][Ag₅I₈] (3) and [Tb(DMSO)₈][Ag₆I₉] (4) (DMSO = dimethyl sulfoxide), have been rationally synthesized, which display simultaneous photochromic and luminescent switchable performances. Photochromism is due to the photolysis of iodoargentate anions and the consequent generation of Ag⁰ particles with surface plasmon resonance (SPR) absorption. Meanwhile, luminescent switchable performance is ascribed to intermolecular fluorescence resonance energy transfer (FRET) from fluorescent solvated lanthanide cations to photochromic iodoargentate anions.