Dependant Visas are for direct family members joining their Sponsors in Hong Kong. Hong Kong residents (e.g. employment, investment, training, student, QMAS and ASSG visa holders) are able to bring along their unmarried dependant children under 18 years old and spouses to Hong Kong. For permanent residents (permanent HKID card holders), they can apply also for their aged dependant parents over 60 years old to join them in Hong Kong. However, dependants of Student Visa holders are not allowed to work in Hong Kong. All dependants are allowed to study.
If your family members are Mainland Chinese residents currently residing in Mainland China, they will not qualify for the dependant visas unless they have secured permanent residency in a foreign country. However, if the Sponsors are admitted to Hong Kong under the Mainland Talents and Professional Admission Scheme, the Sponsors can bring along their unmarried dependant children under 18 years old and spouse to Hong Kong.
If the partners of the Sponsors are not married but only in a common law or defacto relationships, the partners may still be considered for the dependant visas provided that they have formally and legally registered their civil partnership with the respective marriage authority in their own countries. This also applies to same-sex relationship.
For partners whose common law relationships have not been officially registered, then they will not be considered for the dependant visas. They can only apply for a discretionary long-stay visa (a non-resident status) to remain in Hong Kong. Please refer to this page.