Ym mis Mawrth 2021 cafodd rheoliadau eu gwneud  i sefydlu pedwar Cyd-bwyllgor Corfforedig yng Nghymru. Yn ogystal â darparu ar gyfer sefydlu pob un o'r Cyd-bwyllgorau, roedd y Rheoliadau'n cynnwys manylion allweddol megis yr aelodaeth a'r trefniadau cyfansoddiadol craidd, yn ogystal â’r tair swyddogaeth graidd a fydd yn cael eu harfer gan bob Cyd-bwyllgor: cynllunio datblygu strategol; cynllunio trafnidiaeth rhanbarthol; a'r pŵer i wneud pethau i hyrwyddo neu wella lles economaidd eu hardaloedd.
In March 2021 regulations were made to establish four Corporate Joint Committees (CJCs) in Wales. As well as providing for the establishment of each of the CJCs, the Regulations included key details such as membership and the core constitutional arrangements and the three core functions which will be exercised by each CJC: strategic development planning; regional transport planning; and the power to do things to promote or improve the economic well-being of their areas.