Covenant-breaker

A Covenant-breaker or the act of Covenant-breaking is a term used by Bahá'ís to refer to a particular form of what some might call "heresy". (Actually is refers to disunity: "The specific mission of Bahá'u'lláh relates to world unity. Since it would be impossible for the Bahá'í Faith to unite the world if it were itself disunited, the role of the covenant as the guarantor of the unity of the Bahá'í community becomes inextricably linked with the goal of world unity: "It is evident that the axis of oneness of the world of humanity is the power of the Covenant and nothing else." (TDP 49, cf GPB 239, SWA 208-9). http://bahai-library.com/momen_encyclopedia_covenant

Being declared a Covenant-breaker is done by the head of the Faith — which since 1963 refers to the elected nine-member Universal House of Justice, the governing body of the Bahá'ís. Bahá'ís avoid association with them, even if the Covenant-breaker is a family member. The authority to declare a Bahá'í a Covenant-breaker resides solely with the head of the Bahá'í Faith.

Read more about Covenant-breaker:  Definition, Covenant-Breaking in Shoghi Effendi's Immediate Family, Resultant Groups