A prenuptial agreement is valid for a given period of time. In many countries where they are used, they are referred to as ‘sunset‘ clauses because of the time frame. Postnup Before a couple gets married, there are always things to be considered. Bringing in people from different backgrounds to live together requires some sort of an agreement for peaceful coexistence. What has been dominating over time is the prenuptial agreement, popularly known as prenup. It offered a perfect way for settling. IN WITNESS WHEREOF the parties have hereunto set their hands and seals as of the day and year first written above. The same provisions apply to registered partners. The Register of Marriage Settlements contains registered marriage settlements from 1928 up to the present. Your marriage may be the most important legal partnership you'll ever enter. Like business partners, you will have responsibilities, contributions, assets and debts, skills and talents, and more you are bringing to the relationship.