Electrokinetic (EK) soil remediation involves several processes, including transport, electrochemical reactions and thermal effects. These processes interact in a complex way, making it difficult to accurately predict the results. To address this problem, the authors are developing a project called ‘Coupled Numerical Modelling of Electrokinetic Soil Treatments’. The aim of this project is to develop a model that integrates thermal, hydraulic, mechanical, chemical and electrical (THMCE) phenomena during EK treatment. The first phase consists of defining the conceptual model, implementing it in COMSOL Multiphysics and verifying it with reference parameters. The M4EKR model serves as the code base, using the Nernst-Planck equations for species transport and charge conservation together with the electroneutrality condition for electrical charge transport. For chemical reactivity, only the electrolysis of water is considered. Four verification exercises have been carried out to test: (1) Electromigration and electroosmosis with a constant electric potential gradient. (2) Multicomponent electromigration under steady state conditions. (3) Time-dependent multicomponent electromigration. (4) Electromigration with chemical reactivity. The model showed satisfactory agreement with the reference benchmarks in all cases.