Again, I'll point to the example of Sweden, because, over there, very few people actually get married anymore, though very many people have children and pass on their possessions to their children when they die.
You nearly always have joint custody of children, as they are BOTH your children (it doesn't matter if you're married), and inheritance goes to whoever you have in your will. That's why most people in Sweden will have a will - that's something everyone should always do.
Children born to parents in a sambo relationship normally have the same family name as the father unless the parents have agreed to another surname, for example; the mother’s. Two of my cousins, for example, have their mother's surname, and a couple more have their maternal grandmother's surname.
When a married couple split up there are laws governing the disposition of their home and household goods (division of joint property of husband and wife). The sambo law has similar regulations for “sambo” couples who split up. The home is then divided in a similar manner as if they were married.
However, sambo couples do not inherit each other’s assets as married couples do. Since they do not inherit or become beneficiaries of each other’s property, it is important for sambos to have a joint will (last will and testament). A good example of this importance is Stieg Larsson, the renowned Swedish writer who lived sambo for many years with Eva Gabrielsson. When he died in 2004, his father and brother, not Eva, inherited his wealth worth millions. There were law suits and a settlement, but this could have been avoided with a will.
