At the 7T MRI field, the absence of a volume reference coil results in inter channel phase offsets. It is therefore important to understand the impact of using different phase offset correction methods for producing combined phase images. We quantitatively analysed multi-channel offset corrected 7T GRE-MRI phase images of a phantom obtained using five established methods. Magnetic susceptibility images of a brain were assessed qualitatively in addition. We found that methods which phase offset correct using echo time dependent signal phases contain systematic errors, whereas single echo time methods produce more accurate results.