Article 5 Vienna Convention on Diplomatic Relations

1.The sending State may, after it has given due notification to the receiving States concerned, accredit a head of mission or assign any member of the diplomatic staff, as the case may be, to more than one State, unless there is express objection by any of the receiving States.

2.If the sending State accredits a head of mission to one or more other States it may establish a diplomatic mission headed by a chargé d’affaires ad interim in each State where the head of mission has not his permanent seat.

3.A head of mission or any member of the diplomatic staff of the mission may act as representative of the sending State to any international organization.

See also: Article 4 Vienna Convention on Diplomatic Relations