The conditions for a cohabitation agreement to have legal effect are: (1) Both parties to the cohabitation agreement have corresponding civil capacity; （2） True declaration of intention; （3） It does not violate the mandatory provisions of laws and administrative regulations, and does not violate public order and good customs.
 Legal basis:
 Article 143 of the Civil Code of the People's Republic of China
 Civil juristic acts that meet the following conditions are valid:
 （1） The actor has corresponding civil capacity;
 （2） True declaration of intention;
 （3） It does not violate the mandatory provisions of laws and administrative regulations, and does not violate public order and good customs.
 Article 153 of the Civil Code of the People's Republic of China
 Civil legal acts that violate the mandatory provisions of laws and administrative regulations are invalid. However, the exception is that the mandatory provisions do not invalidate the civil juristic act.
 Civil juristic acts violating public order and good customs are invalid.