Before conclusion of the marriage
Because an antenuptial contract only becomes effective after solemnization of the marriage, there is no reason why the parties thereto cannot exercise their common law right to amend or to cancel such a contract by agreement (RCR 33 of 1954, RCR 53 of 1966 and RCR 4 of 1969). Such an amending agreement or notarial deed of cancellation will, naturally, have to be entered into before the conclusion of the marriage and, in order to be effective against third parties, also be registered in the deeds office. If it is not registered in a deeds registry it will only be effective inter partes. The amending deed will be given an antenuptial contract number by the deeds registry concerned.
If, after executing an antenuptial contract, the parties decide not to proceed with the marriage, it can also be cancelled by the court on application (Cross v Gardner 1914 CPD 355; Ex parte Holm 16 SC 351). The Court has also cancelled an antenuptial contract when the parties changed their minds before marriage and decided rather to be married in community (Ex parte Le Roux and Another 1913 CPD 11).
Where both deeds (i.e. the original agreement and the amending agreement) are lodged simultaneously for registration, both deeds are registered and numbered as one deed. If, however, the amending agreement is lodged at a later stage, that is after registration of the original agreement, a Hcode is allocated to it and it is registered separately (RCR 33 of 1954). In the latter case, the original deed will be endorsed re the amending deed.
After conclusion of the marriage
It is a general rule in our law that an antenuptial contract cannot be amended inter partes after conclusion of the marriage (Ex parte De Zwaan and Another 1909 TS 676)).
Such a contract can, however, be amended by the Court, but only in a very limited sense. In Ex parte Venter et Uxor 1948 (2) SA 175 (O), it was held that the court's power to authorize the revocation or amendment of antenuptial contracts, is strictly limited to those cases where the marriage is dissolved or where the contents of the written contract did not give effect to the actual agreement between the parties.