The goal of this study was to evaluate the applicability of a framework for a good biofilm reactor modelling practice (GBRMP) to moving-bed biofilm reactor (MBBR) and integrated fixed-film activated sludge (IFAS) systems using a the commercially available water resource recovery facility (WRRF) simulation tool GPS-X (Hydromantis; Hamilton, ON, Canada). We tested the previously proposed calibration protocol using data from a pilot-scale MBBR and a pilot-scale IFAS systems. Both pilot-scale systems were modelled using a 1-D biofilm model and ASM1 as the process model. The MBBR model was successfully calibrated following the GBRMP calibration approach. However, calibration of the IFAS model was more difficult, as both biofilm and activated sludge related parameters needed to be calibrated with a similar set of available data as for the MBBR. For IFAS model calibration, we modified the GBRMP protocol by integrating activated sludge related variables and parameters to the calibration approach. We recommend the development of an expanded calibration protocol that incorporates criteria for calibrating both suspended growth and biofilm models when simulating hybrid (IFAS) reactors.