Postnuptial and prenuptial agreements are pretty much the same except for one small detail. U.S. News and World Report explains the difference between the two types of agreements is one occurs before the marriage and the other occurs after the marriage.
A postnuptial agreement is something you create once you are in the marriage. The prenuptial agreement comes before your marriage. This detail may alter things slightly in terms of what goes into the agreement.
A postnuptial agreement may be easier to create because you already have intimate knowledge of your spouse’s finances and your combined financial situation. Your eyes are more open than they would be with a prenuptial agreement. Plus, you are already past the wedding and the honeymoon. You are in the nitty-gritty of everyday life, so you can approach it more logically.
Proposing any type of marital agreement can be awkward, but a postnuptial agreement may be very difficult, especially if you spring it on your spouse. It can make the other person wonder if your relationship is in trouble since these agreements do not come into play unless you get a divorce. However, if you have a good relationship and approach the idea together, it may be much easier to create a postnuptial agreement.
While the two agreements will do essentially the exact same things, because you have experience and knowledge with a postnuptial agreement, it may make for a better overall contract. You go into it knowing the full situation and can work together fairly on deciding what goes in it and how it will work out in the end.