That is a very good question, thanks for asking it. It does seem a little bit looney to sign a post-nup after you got married without a prenup, doesn’t it? But that is based on a wrong assumption because many people who sign a post nup also had a prenup. Not all. But many people.
The prenup is obviously before marriage and the post nup is after marriage.
Why do people sign prenups? To protect their financial interests and reduce fights over money if the marriage fails. That is the basic reason.
Why do they sign post nups? Pretty much the same reason. But after marriage certain factors and circumstances can change necessitating a marital agreement that is in lieu of one that was executed before the marriage or that is completely independent and stand-alone.
For example, let’s say after marriage a couple finds that they simply have different ideas of how to handle money and they are fighting a lot about it. One spouse, for example, wants to put a huge amount of money into the stock market and the other is totally risk-averse and wants to put the money in rental real estate. This couple has such fundamentally different ideas about money that their marriage is about to explode. They probably should just get a post nup and handle their own money. This could actually end up saving their sanities and marriage. Or let’s say a spouse is about to inherit a lot of money, a family business, or something of that nature. It makes sense to get a post nup.
There are many other reasons that could justify getting a post nup and there is nothing at all crazy or out of mind about it.
As in the case of prenups, it is vital that there are honesty and full disclosure of assets – maybe it is even more vital than with a prenup because now you owe your spouse a duty of honesty just based on the underlying marriage contract which was absent when you signed a prenup. So full disclosure is essential or the post nup could be challenged. And it is advised to get separate counsel as well.