Unmarried couples don’t inherit each other’s property automatically. Married couples are often protected by state intestacy laws, even if they don’t have a will, so the survivor of a married couple will inherit at least a portion of the deceased spouse’s property.
Unmarried couples don’t have the right to speak for each other in a medical emergency. For example, if your partner loses consciousness or capacity, someone will have to make medical decisions. Unless you’ve filed certain paperwork, you aren’t legally able to make those decisions.
Unmarried couples can’t handle the other’s finances in a crisis. Married couples with joint assets are less affected by this issue.