CMP343 is one of the Connection and Use of System Code (CUSC) Modifications to implement the Transmission Demand Residual (TDR) reforms in line with Ofgem’s Targeted Charging Review Decision. CMP343 proposes the methodology for TDR charges to be applied only to ‘Final Demand’ on a ‘Site’ basis, as well as how to treat negative locational charges and the application of any charging bands.