This article reviews prior research on connections between through-plates and circular hollow sections (CHS) and presents a finite element (FE) study validated against laboratory experiments. The FE analysis indicates that, for a given geometric configuration, the behaviour of through-plate-to-CHS connections closely matches the sum of branch-plate-to-CHS connection behaviour in plate tension and compression. A connection design strength, which is shown to be valid for a wide range of connection geometries and which is the sum of existing design recommendations for branch plate-to-CHS connections loaded in axial tension and compression, is hence proposed for through-plate-to-CHS T-connections. This therefore enables maximum advantage to be taken of the capacity of this type of “reinforced” tubular connection.