HVDC transmission systems are key enabler in the energy transition, connecting renewables and load centres through long distance and high-capacity links. Minimisation of the footprint required is particularly relevant for HVDC equipment as it is often applied in space constrained locations. For this reason, HVDC gas-insulated systems have been developed by several manufacturers including metal-enclosed HVDC GIS cable connection assemblies, the qualification of which has been a subject of discussion due to a mismatch between the recommended test approaches for cable and GIS technologies. This technical brochure provides recommendations for the dielectric testing of HVDC GIS cable connection assemblies based on a comparison of the simulated electric field strengths resulting from cable system and GIS test approaches.