To ensure the Welsh Government’s policies are developed with consideration to the short, medium, and long-term impacts on the Welsh tax base.
Sicrhau bod yr effeithiau byrdymor, tymor canolig a hirdymor ar y sylfaen drethu Gymreig yn cael eu hystyried wrth fynd ati i ddatblygu polisïau Llywodraeth Cymru.