I had this exact issue come up a few days ago. Someone is getting married and wanted to get a prenup. They then changed their mind and said they would just update their wills instead. Both documents are good to have and they each can do different things. But does one outweigh the other?
Prenup
Prenuptial agreements are written contracts between two people planning to get married. The agreement typically lays out what property and debts each person has. This contract usually lists all of property and debts each person has, and lays what rights each person will have in regards the property and debts in case the marriage should end. But, a prenup can play a role in how property is divided after death.
Benefits over a will
Sine prenups are legal contracts between two people then they will often be the governing document upon the death of one of the spouses. The agreement is still valid and enforceable if the other party to the agreement is still alive and able to receive the property.
Another benefit is that a prenuptial can contain a forum selection clause. These are standard in pretty much all contracts. These clauses state which state’s laws will apply should there be an issue with the contract. Therefore the living spouse could choose to have the agreement enforced in a different state other than the will. Wills cannot have these clauses.
One other thing a prenup can do that a will cannot is allow you to leave out your spouse. The whole purpose of a prenup is to determine how property is divided in case of divorce. You could very well contract to give your spouse nothing. Now this could raise issues of fairness which is important when it comes to a prenup, but it is a possibility. It is generally illegal to disinherit your spouse in your will.
Will
A will is a document written by a person laying out how they want their property distributed upon their death. A will only covers the person writing it, not the spouse.
Benefits over a prenup
Prenups can and sometimes are found to be unenforceable. Reasons could be they were signed too close to the wedding date, one party did not have a lawyer, or as I mentioned above it was not fair. If this happens then the will rules.
While both documents serve a specific purpose there can be some overlap. It is important to understand the differences, similarities, and know what you want to accomplish. As always consult with an attorney to find out what may be best for you.