Where contracts were exchanged before 10 October 2022 and the contract was substantially performed before that date (refer to LTTA/2150 for further information on substantial performance).
Pan fo contractau wedi’u cyfnewid cyn 10 Hydref 2022 a bod y contract wedi’i gyflawni’n sylweddol cyn y dyddiad hwnnw (cyfeiriwch at TTTD/2150 am ragor o wybodaeth am gyflawni’n sylweddol).