I develop a new estimate of core inflation for New Zealand and Australia based on a dynamic factor model. By using an over-identification restriction, the factors of the model are classified as tradable and nontradable factors. This innovation allows us to examine the relative contributions of tradable and nontradable prices towards core inflation. The results show that core inflation in both countries is primarily driven by the nontradable factor. The nontradable factor also explains significantly more of the variance in headline inflation relative to the tradable factor. Finally, both the tradable and nontradable factors show similar profiles across both countries suggesting common drivers.