Caiff rhai o'r mesurau hyn eu cynnwys ym Mil Llywodraeth Leol ac Etholiadau (Cymru) 2019 a chaiff rhai eu darparu trwy ddiwygiadau i Reoliadau Ardrethi Annomestig (Eiddo heb ei Feddiannu) 2008. Deuant i rym o 1 Ebrill 2021, i gyd-fynd â gweithredu'r rhestr ardrethu a'r ymarfer ailbrisio nesaf. Mae hyn yn rhoi amser i Lywodraeth Cymru godi ymwybyddiaeth o'r newidiadau ymhlith talwyr ardrethi ac i gyrff eraill paratoi ar gyfer y newidiadau.
Some of these measures will be included in the forthcoming Local Government and Elections (Wales) Bill 2019 and some will be delivered by amendments to the Non Domestic Rating (Unoccupied Property) (Wales) Regulations 2008. They will come into force from 1 April 2021, aligned with the implementation of the next rating list and revaluation exercise. This provides time for the Welsh Government to raise awareness of the changes with ratepayers and for local authorities and other bodies to prepare for the changes.