Thomas started his lawyer carrier in september 2004, with the lawfirm DLM Association under the direction of Philippe Levert. He joined CMS Debacker in 2009, in order to be able to practice his subjects of predilection, namely legal assistance and litigation in the field of real estate projects and classified installations (town planning permissions, environment permissions, socio-economique permissions, expropriation, pre-emption, legal constraint of public utility, domaniality,…).