When data is received through the returns, validation checks are performed by Welsh Government statisticians and queries referred to local authorities where necessary.
Caiff yr adroddiadau cysoni wedyn eu dosbarthu i awdurdodau lleol, a gofynnir iddynt gadarnhau cywirdeb eu data a/neu fynd i'r afael ag unrhyw bryderon ynghylch ansawdd y data.