Mae Rhan 2 o Ddeddf Cymru 2014 yn darparu ar gyfer datganoli cyfres o bwerau cyllidol i Gymru. Mae’r rhain yn cynnwys galluogi’r Cynulliad Cenedlaethol i ddeddfu ar gyfer trethi Cymreig ar drafodiadau’n ymwneud â buddiannau mewn tir a gwarediadau tirlenwi; deddfu ar gyfer ei weithdrefnau cyllidebol ei hun a deddfu i alluogi Llywodraeth Cymru i fenthyca er mwyn cyllido gwariant cyfalaf a rheoli amrywiadau cyllidebol yn sgil datganoli trethi.
Part 2 of the Wales Act 2014 provides for the devolution of a range of financial powers to Wales. These include enabling the National Assembly for Wales to legislate for Welsh taxes on transactions involving interests in land and disposals to landfill; to legislate for its own budgetary procedures and for the Welsh Government to borrow to fund capital expenditure and manage budgetary fluctuations arising from tax devolution.