You can ask the registrar for general advice at the time of registration or seek your own legal advice on how many certificates you may need before the appointment.
Gallwch ofyn i'r cofrestrydd am gyngor cyffredinol wrth gofrestru neu ceisiwch eich cyngor cyfreithiol eich hun o ran faint o dystysgrifau y bydd eu hangen arnoch o bosib cyn yr apwyntiad.