What’s the difference between a prenup and a postnup? Not much. And both are increasingly popular
There’s one major difference between a prenuptial agreement and a postnuptial agreement, and that’s the timing. A prenuptial agreement is made before marriage, a postnuptial is made afterwards.
Otherwise, prenups and postnups essentially do the same: setting out how a couple’s assets will be divided if they split.
Both prenups and postnups offer:
- a simple and sensible alternative to haggling over who will retain which assets should the relationship sour or having to leave it to the law to decide
- a way to ringfence any assets you bring to your marriage. This can protect assets which you ultimately want to benefit your children from a previous relationship or even other family members.
The two Ps compared
Of the two types of agreement, postnups have a lower profile, but their flexibility makes them a useful option to consider. For example, they can be used if you did not make a prenup, or want to update a prenup after marriage to cater for the arrival of children, a windfall or the restructure of a business.
Postnups also provide time and space. Both agreements may only be overturned by a court if they are shown not to be fair and reasonable at the time that they are entered – for example, neither partner should face undue pressure to sign. A rushed prenup signed as you organise 25 last-minute wedding arrangements may appear less reasonable than a postnup agreed in less haste!
Published 16 October 2025
