In most cases we will need to see original supporting documents such as a letter from your landlord if advising of a rent increase or wage slips if your wages have changed.
Yn y rhan fwyaf o achosion, bydd angen i ni weld dogfennau ategol gwreiddiol megis llythyr gan eich landlord os yw'n rhoi gwybod am godi rhent neu slipiau cyflog os yw'ch cyflog wedi newid.