Ar 23 Medi 2014, lansiais y Papur Gwyn 'Casglu a rheoli trethi datganoledig yng Nghymru', yn ceisio safbwyntiau ar gynigion Llywodraeth Cymru ar gyfer gweinyddu trethi datganoledig. Daeth yr ymgynghoriad i ben ar 15 Rhagfyr.
On 23 September 2014, I launched the White Paper 'Collection and management of devolved taxes in Wales', seeking views on the Welsh Government's proposals for administering devolved taxes.  The consultation closed on 15 December.