Deals about what should happen to property owned before a marriage in the event of a divorce could be made legally binding under options being considered by the Law Commission.
But any future law could make a distinction between any property or wealth acquired by each person before a marriage and that gained as a couple, the body which reviews and reforms law in England and Wales said.
Professor Elizabeth Cooke, the Law Commissioner leading the consultation, said: "We think it's very important to raise that option because so often people talk about pre-nups and post-nups as if they are one thing. They could cover all the assets, they could cover just the royalties from the band you played in 30 years ago, just the piano, or just the inheritance."
In the consultation documents, the Commission went on: "The ability to agree in advance what property is non-matrimonial and to 'ring fence' it in a binding marital property agreement may be attractive to some people. The consultation paper therefore asks, first, whether couples should be able to enter into a binding agreement not to seek ancillary relief in the event of divorce or dissolution and, secondly, whether such agreements should be able to encompass all of a couple's property or to contain only terms relating to pre-acquired, gifted or inherited property."
The Law Commission is considering whether a new approach to pre-nuptial, post-nuptial and separation agreements is needed to give couples more certainty over what would happen to their property, while also retaining safeguards to protect vulnerable spouses and children.
It comes after German heiress Katrin Radmacher's long legal battle with her former husband over her £100 million fortune gave the deals greater power in the courts in determining how a couple's assets are split.
But courts still have to decide whether such agreements are enforceable on a case-by-case basis, which can lead to "uncertainty and expensive litigation", the Commission said.
Prof Cooke added: "This is a very emotional area. Some feel that where couples have reached agreement, the courts should not be involved; yet the courts' approach is primarily protective, and some feel that they should not be wholly excluded.
"Our consultation paper considers the arguments for and against reform and examines how a new approach might balance the desire of some couples to plot their own future with more certainty against the need for safeguards against exploitation and the creation of hardship. This is an issue that needs to be handled with care."
The consultation runs until April.