Current design standards for offshore open-ended piles vary in their consideration of the soil plug’s contribution to the pile’s axial capacity and, indirectly, to its stiffness. API RP2 GEO (2011) and UWA-05 (Lehane et al., 2005) consider the contribution of the plug, but ICP-05 (Jardine et al., 2005) combines the plug capacity with the end bearing from the pile annulus. The current study critically examines the behaviour of the plug using a specifically-designed 1D finite element method, developed to model each component of the plug-pile-soil interaction. The load-transfer into the surrounding soil and base is modelled using non-linear axial soil reaction curves. Using this methodology, a theoretical assessment of the contribution of the soil plug to the pile axial performance can be made. The findings of this theoretical assessment are compared to the current treatment of soil plug response in the design standards.