A letter of credence (French: Lettre de créance) is a formal diplomatic letter that designates a diplomat as ambassador to another sovereign state. Commonly known as diplomatic credentials, the letter is addressed from one head of state to another, asking them to give credence (French: créance) to the ambassador's claim of speaking for their country. The letter is presented personally by the ambassador-designate to the receiving head of state in a formal ceremony, marking the beginning of the ambassadorship.
Letters of credence are traditionally written in French, the lingua franca of diplomacy.[1] However, they may also be written in the official language of the sending state.[2][3]
Letters of Credence (translated from French) of Jan Kułakowski, 26 February 1990 (AMFA).