Declarations of legal cohabitation

Legal cohabitations are rather stable in 2018

Legal cohabitations are rather stable in 2018

With 38,921 new declarations in 2018, legal cohabitations are rather stable (-0.3 % compared to 2017). However, terminations of legal cohabitations are on the rise (+4.4 %).

There is a slight increase in the average duration of cohabitation: from 4.3 years in 2017 to 4.6 years the following year. Marriage remains the first cause of legal cohabitation termination.

Most couples are formed around the age of 30

In 2018, it is still around the age of thirty that single partners enter into legal cohabitation for the first time, on average at 31.4 years for the first cohabitant and 29.4 years for the second. The age difference in the couple does not vary: 2 years



Legal cohabitation declarations

Evolution of the number of legal cohabitation declarations per year and administrative unit, since 2000

Administrative unit Year
2000 2005 2010 2015 2017 2018
Belgium 2,694 15,513 36,962 40,770 39,038 38,921
Brussels-Capital Region 121 1,594 2,957 3,125 2,817 2,803
Flemish Region 2,040 7,569 21,928 23,335 23,332 23,098
Walloon Region 533 6,350 12,077 14,310 12,889 13,020
Legal cohabitation terminations

Evolution of the number of legal cohabitation terminations per year and administrative unit, since 2000

Administrative unit Year
2000 2005 2010 2015 2017 2018
Belgium 111 3,299 13,487 22,227 24,764 25,852
Brussels-Capital Region 5 271 909 1,340 1,383 1,412
Flemish Region 83 1,909 7,779 13,326 15,017 15,785
Walloon Region 22 1,039 4,472 7,099 7,966 8,310

Statbel publishes for the first time this year a statistic on the declaration of legal cohabitation using the National Register of Natural Persons (RNPP). According to the law of 23 November 1998 establishing legal cohabitation (published in the Belgian Official Journal on 12 January 1999), two persons living together have the possibility, since 1st January 2000, to officially confirm the fact that they live together. Therefore, there is legal cohabitation when two persons living together make a declaration to this effect to their local authorities, irrespective of their sex and relationship. The conditions for such a declaration are the following:

  • having the legal capacity to enter into a contract
  • not being married
  • not being in a legal cohabitation with another person The civil registrar is required to verify compliance with the legal conditions and to register the declaration in the RNPP.

In Belgium, legal cohabitation refers in principle to a situation where two persons live together. However, we have been able to detect some rare cases of registration of legal cohabitation through consular offices abroad.

The current statistic is produced using the information type “legal cohabitation” (I.T. 123) of the RNPP. The I.T. 123 registers a series of data relating to legal cohabitation, including the date of the declaration, the place of registration of the declaration (municipality of residence), the presence of a notarial contract (with the date and place of signature), the date and the reasons of termination. By coupling this information with other I.T. in the RNPP, we can characterise the cohabitants and create tables based on the sex, the age, the nationality, etc. A foreigner residing illegally on the territory can legally enter into legal cohabitation provided that he/she, together with the person with whom he/she is living, has a common principal residence in Belgium.

However, this statistic does not include any cases of two persons living together who are registered in the waiting register. In order to get a coherent statistic, we also have excluded some rare cases where there is a contradiction between the civil status and the situation of legal cohabitation (clearly married (or divorced) persons based on a “reasonable” observation period; cases related to a late - but “reasonable” - registration of divorces are therefore included in the statistics).