For councils, administering these calculations is complex and obtaining this information to support the application for a reduction can be time-consuming, leading to delays in assessments.
I gynghorau, mae gweinyddu'r cyfrifiadau hyn yn gymhleth a gall gymryd amser i gael gafael ar yr wybodaeth hon i gefnogi'r cais am ostyngiad, gan arwain at oedi wrth asesu.