It is unclear in what circumstances such appeals would be necessary and the ability to do so may not be compatible with their role as the billing authority within the NDR system.
Nid yw'n glir o dan ba amgylchiadau y byddai angen apelau o'r fath ac efallai na fyddai'r gallu i wneud hynny yn gydnaws â'u rôl fel yr awdurdod bilio o fewn y system ardrethi annomestig.