A diplomatic mission is a group of people from one nation state present in another nation state to represent the sending state in the receiving State. In practice, a diplomatic mission usually denotes the permanent mission, namely the office of a country's diplomatic representatives in the capital city of another country. Under international law, diplomatic missions enjoy an extraterritorial status and thus, although remaining part of the host country's territory, they are exempt from local law and in almost all respects treated as being part of the territory of the home country.
A permanent diplomatic mission is usually known as an embassy, and the head of the mission is known as an ambassador. Missions between Commonwealth countries are known as High Commissions and their heads are High Commissioners. All missions to the United Nations are known simply as Permanent Missions, and the head of such a mission is typically both a Permanent Representative and an ambassador. Some countries have more idiosyncratic naming for their missions and staff: a Vatican mission is headed by a Nuncio and consequently known as an Apostolic Nunciature, while Libya's missions are People's Bureaus and the head of the mission is a Secretary.
In the past a diplomatic mission headed by a lower ranking official (i.e. envoy or minister resident) was known as a legation. Since the ranks of envoy and minister resident are effectively obsolete, the designation of legation is no longer used today. (See diplomatic rank.)
In cases of dispute, it is not uncommon for a country to recall its head of mission as a sign of its displeasure. This is less drastic than cutting diplomatic relations completely, and the mission will still continue operating more or less normally, but it will now be headed by a chargé d'affaires who may have limited powers. Note that for the period of succession between two heads of missions, a chargé d'affaires per interim may be appointed as caretaker; this does not imply any hostility to the host country.
A Consulate is also a diplomatic office, but undertakes a more restricted range of duties as defined by the Vienna Convention on Consular Relations.
The term "embassy" is often used to refer to the building or compound housing an ambassador's offices and staff. Technically, "embassy" refers to the people of the mission, while the office building in which they work is known as a chancery, but this distinction is rarely used in practice. Ambassadors reside in ambassadorial residences, which enjoy the same rights as missions.
The role of such a mission is to protect in the receiving State the interests of the sending State and of its nationals, within the limits permitted by international law; negotiating with the Government of the receiving State as directed by the sending State; ascertaining by lawful means conditions and developments in the receiving State, and reporting thereon to the Government of the sending State; promoting friendly relations between the sending State and the receiving State, and developing their economic, cultural and scientific relations.
Between members of the Commonwealth of Nations embassies sometimes have an additional role. It is generally expected that an embassy of a Commonwealth country in a non-Commonwealth country will do its best to provide diplomatic services to citizens from other Commonwealth countries if the citizen's country does not have a embassy in that country. (eg. If a South African citizen found him/herself in need of the services of an embassy in Thailand, it is generally understood that he/she could go to the Canadian Embassy and be provided with some help in obtaining the necessary services.)
The rights and immunities (such as diplomatic immunity) of diplomatic missions are codified in the Vienna Convention on Diplomatic Relations.
- List of embassies and high commissions