The Act operates to enable changes to be made to the Welsh Tax Acts in certain circumstances and for a specified period, through regulations made by the Welsh Ministers.
Diben y Ddeddf yw sicrhau ei bod yn bosibl gwneud newidiadau i Ddeddfau Trethi Cymru o dan rai amgylchiadau penodol ac am gyfnod penodedig, drwy reoliadau a wneir gan Weinidogion Cymru.