How do organizations and non-member states get observer status in the General Assembly?

The United Nations General Assembly may grant non-member states, international organizations and other entities Permanent Observer Status.

The UN Charter and the General Assembly Rules of Procedure have no provisions related to granting permanent observer status.

The process is described in a legal opinion of 15 August 2008, published in the 2008 United Nations Juridical Yearbook, p. 438 (in English), part B, paragraphs 8-11. The legal opinion cites decision 49/426 of 19 December 1994, (attached) in which the General Assembly decided that observer status would be confined to States and intergovernmental organizations whose activities cover matters of interest to the Assembly. 

In accordance with paragraph 2 of A/RES/54/195, the Sixth Committee of the General Assembly considers applications for observer status before they are considered in the plenary session. 

Permanent Observers may participate in the sessions and workings of the General Assembly and maintain missions at the UN Headquarters.

A list of non-Member States, entities and organizations having received a standing invitation to participate as observers in the sessions and the work of the General Assembly is issued annually as a document in the  A/INF/session/-- series.