Phase images from EPI and GE acquisitions differ due to the divergent acquisition schemes and reconstruction steps. The effect of these is investigated both in measured phase and estimated susceptibility values. We show that non-ΔB0-related phase is present in phased array data combined with the Virtual Receiver Coil and Roemer approaches and that this influences estimated susceptibilities. For EPI, data can be combined using a multi-echo “ASPIRE” GE prescan, leading to minimal non-ΔB0-related phase. There was large variability of in-vivo EPI fieldmaps due to physiological noise and non-linearities in phase evolution in both GE and EPI data.