Letters of Credence

Letters of Credence (lettres de créance) are the foundational instrument by which one sovereign formally introduces its ambassador to another. Signed by the sending head of state and countersigned by the foreign minister, they are addressed personally to the receiving head of state and request that 'full faith and credit' be given to the bearer in all matters communicated on behalf of the sending state.

The practice is codified in the Vienna Convention on Diplomatic Relations (1961). Article 13 specifies that the head of mission is considered to have taken up functions either when credentials are presented or when arrival is notified, depending on the receiving state's practice. Article 4 separately governs agrément, the prior consent required before a person can be named ambassador.

Two related documents accompany the process:

• Letters of Recall (lettres de rappel): formally terminate the predecessor's mission and are typically presented alongside the new credentials.
• Letter of Commission: used for chargés d'affaires, who are accredited by the foreign minister rather than the head of state and thus do not present credentials to the sovereign.

The presentation ceremony itself remains highly ritualized. In the United Kingdom, ambassadors traditionally arrive at Buckingham Palace in a state carriage. In the United States, credentials are presented to the President at the White House, often in grouped ceremonies. Until credentials are formally presented, an ambassador generally cannot exercise the full functions of office, though they may begin administrative work and informal contacts.

The legal effect is significant: presentation marks the point from which the diplomat enjoys the full protocol rank determined by date and time of accreditation, governing precedence within the diplomatic corps under Article 16 of the Vienna Convention.