While sufficient progress has been made to demonstrate that the AHD can be significantly upgraded using the currently available data-sets, improvements to these data-sets are required to fully realise a scientifically rigorous new vertical datum. Here we detail the improvements that need to be made to the existing data-sets. The Geoscience Australia-provided Australian National Levelling Network (ANLN) file needs updating, plus targeted re-observation in areas of office-identified errors. Date and time of observation plus weather conditions need to be added to the ANLN to allow the effects of atmospheric refraction to be corrected retrospectively. More GPS observations with connections to the ANLN are required, while dubious connections must be validated. Up to 200 tide gauges around Australia need to be connected to the ANLN and their MSL values brought together to a common epoch. The re-adjustment of the new vertical datum can then be constrained (not fixed) at tide gauges to the CARS2006 climatological sea surface topography model. These tasks will be very labour intensive and require additional resources for all Australian geodetic agencies. These data-set improvements would provide long-term benefits by increasing the longevity of any updated vertical datum, while immediately satisfying the increasing levels of accuracy required by scientific and commercial users.