In this work, we report a comprehensive experimental study of the oxide-ion dynamics of both Bi 0.913 V 0.087 O 1.587 and Bi 0.852 V 0.148 O 1.648 using multinuclear variable-temperature solid state nuclear magnetic resonance (VT-NMR), and compare the conduction mechanisms of these phases to the P-substituted analogue Bi 0.852 P 0.148 O 1.648 . These VT-NMR experiments can distinguish amongst crystallographic oxygen environments present in the phases as well as their corresponding motional processes and rates. In this study, we have used . We also find that the concentration of dopant is critical for maximising the rate of conduction, with higher dopant concentrations leading to the formation of VO x polyhedra that do not participate in ionic conduction pathways and instead hinder the overall movement of oxide ions through the structure. Furthermore, the use of dopant atoms that are unable to support variable O coordination (e.g., P) hinders exchange between the two sublattices; this finding helps to explain previous reports of oxide-ion conductivity about half an order of magnitude lower for the P-substituted phase relative to the β -Bi 46 V 8 O 89 material over the same temperature range. Experimental Methods