Legislation is different for cohabitants than for married couples. While a division of property that follows a divorce is regulated by law, a division of property that follows dissolution of cohabitation is not regulated by law.
The legal position of the collector is therefore proportional to that of the spouses. In general, you can say that you take with you the belongings that belong to you, i.e. those that were brought into the relationship and those that were acquired during the undocumented cohabitation.
It looks simple, but in reality it is often very complicated. Most undocumented couples have joint finances while living together, and it is therefore difficult to have an overview of what belongs to one and what belongs to the other, especially when the cohabitation has lasted for many years.
It is often a good idea to contact a lawyer during cohabitation and draw up a cohabitation contract. When breaking up a cohabitation, a lawyer can help to get an overview of a situation that often seems unmanageable.