The Kanmantoo Copper Mine (KCM) ceased open pit operations in 2019 and commenced the development of an Underground Operation in 2023. This switch in operation type created a new challenge in the way geological information including grade estimations are integrated into the development of a Mine Plan suitable for a selective underground Mining Method. The Kanmantoo Cu-Au-Bi-Ag deposit is hosted within Cambrian age metamorphosed sediments with copper distribution controlled by sulfide dominant veins and vein stockworks located within a shear system. This mechanism of mineralisation provides unique challenges such as discontinuous mineralised veins, varying veining abundance, changing plunge and dip of mineralisation across the lode systems, varied intensity of alteration and deposit scale boudinaging. These geological considerations need to be a central to the development of a mine plan in order to achieve maximum economic return from the mining sequence, while also giving consideration to the geological uncertainty when determining mining sequence. To achieve the most robust mine plan the information requirements for the end users of the geological interpretations needs to be considered in the determination type of estimations that are created. This allows the information collected from geological observation and drill hole information to be integrated into mine plans and appropriate geological confidence levels can be accounted for in the Mine Planning process. As a result the development of the geological estimation methodology at Kanmantoo has developed significantly to facilitate the end goal of a robust mine plan that honours the geological variability and identifies variability in information confidence while honouring the geology of the deposit.