Yes, a cohabitation agreement can be overturned. When the court reviews the contract, it will consider the provisions mentioned in the document and check whether they are grossly unfair.
This could mean the agreement favors one partner to such a degree that the other partner would be financially disadvantaged or have their quality of life significantly reduced.
The court will also scrutinize the agreement if children are involved, as they will only approve contractual agreements in the children’s best interests.