Ar 8 Mawrth, cytunodd Cynulliad Cenedlaethol Cymru yn unfrydol ar Ddeddf Casglu a Rheoli Trethi (Cymru) 2016 a chafodd y Ddeddf Gydsyniad Brenhinol ym mis Ebrill 2016. Mae'r Ddeddf yn gosod sylfeini ein cyfundrefn ar gyfer trethi datganoledig, gan gynnwys sefydlu Awdurdod Cyllid Cymru. Mae'r pwerau yn y Ddeddf yn rhoi'r hyblygrwydd i Awdurdod Cyllid Cymru, fel awdurdod trethi newydd, i dynnu ar allu cyrff eraill drwy ddirprwyo ei swyddogaethau casglu a rheoli trethi.
The Tax Collection and Management (Wales) Act 2016 was agreed unanimously by the National Assembly for Wales on 8 March and received Royal Assent in April 2016. The Act establishes the foundations for our devolved tax regime, including the establishment of the Welsh Revenue Authority (WRA). The powers within the Act provide the WRA with flexibility, as a new tax authority, to draw on the capacity and capability of other bodies by delegating its tax collection and management functions.