This is a discussion paper for initiating an on-going conversation on “Initial Registration of 3D Parcels” in the working session at the 4th International Workshop on 3D Cadastres. The working session will focus on 3D registration from multiple points of view. Figure 1 shows the aspects of 3D registration that will be discussed in the working session. The aim of the discussion is to critically analyse the most distinguishing features of 3D registration. Concentrating on the main topics and their related sub-topics will enable to further consolidate experiences and knowledge on the primary step towards the realisation of 3D cadastre.