People, circumstances and relationships are all prone to change over time and the understanding you had when you first married, or even the distribution of your wealth and assets, may have evolved over the years. For example, one of you may now run a successful business, while the other has stayed at home to look after the children. Unless you have jointly acquired finances, this might leave one partner fearful of what the future holds, perhaps after the children have left home. A postnuptial agreement can be a way of providing reassurance by redistributing assets more fairly, and by ensuring that neither of you has to worry about your financial future.