In the United Kingdom, the Accession Council is a ceremonial body which assembles in St. James's Palace upon the death of a monarch (Demise of the Crown), to make a formal proclamation of the accession of his or her successor to the throne, and to receive a religious oath from the new monarch. However, the proclamation has no legal force, as the succession will have automatically passed to the new monarch under the terms of the Act of Settlement 1701.
The Council is made up of Privy Counsellors, members of the House of Lords, the Lord Mayor of the City of London, the Aldermen of the City of London and the High Commissioners of some Commonwealth countries.
The Council's Proclamation of Accession, which confirms the name of the heir, is signed by all the attendant Privy Counsellors. The Proclamation is traditionally read out at several traditional locations in London, Edinburgh, Windsor, and York. It is also read at a central location in each town or village. The most recent proclamation was as follows:
- Whereas it has pleased Almighty God to call to His Mercy our late Sovereign Lord King George the Sixth of Blessed and Glorious memory, by whose Decease the Crown is solely and rightfully come to the High and Mighty Princess Elizabeth Alexandra Mary:
WE, therefore, the Lords Spiritual and Temporal of this Realm, being here assisted with these His late Majesty's Privy Council, with representatives of other Members of the Commonwealth, with other Principal Gentlemen of Quality, with the Lord Mayor, Aldermen, and Citizens of London, do now hereby with one voice and Consent of Tongue and Heart publish and proclaim that the High and Mighty Princess Elizabeth Alexandra Mary is now, by the death of our late Sovereign of happy memory, become Queen Elizabeth the Second, by the Grace of God Queen of this Realm and of all Her other Realms and Territories, Head of the Commonwealth, Defender of the Faith, to whom Her lieges do acknowledge all Faith and constant Obedience with hearty and humble Affection, beseeching God by whom Kings and Queens do reign, to bless the Royal Princess Elizabeth the Second with long and happy Years to reign over us.
The proclamation is not always worded consistently; for instance, on the accession of George VI, the proclamation had to be reworded because Edward VIII had abdicated, rather than died, and "Emperor of India" was added at the end of the list of titles until that title was relinquished by George VI.
Religious oath 
The new Sovereign, who is traditionally present, takes an oath to preserve and defend the Church of Scotland. (Elizabeth II was in Kenya when she acceded to the throne, and the Accession Council therefore met twice, first for the proclamation and again so that the new Queen could take the oath.) The provision in Article XXV Section II of the Acts of Union 1707 states with respect to confirmed Acts of Scotland:
- And further Her Majesty with Advice aforesaid expressly declares and statutes that none of the Subjects of this Kingdom [Scotland] shall be liable to but all and every one of them for ever free of any Oath Test or Subscription within this Kingdom contrary to or inconsistent with the foresaid true Protestant Religion and Presbyterian Church Government Worship and Discipline as above established and that the same within the Bounds of this Church and Kingdom shall never be imposed upon or required of them in any sort And lastly that after the decease of Her present Majesty (whom God long preserve) the Soveraign succeeding to Her in the Royal Government of the Kingdom of Great Britain shall in all time coming at His or Her Accession to the Crown swear and subscribe that they shall inviolably maintain and preserve the foresaid Settlement of the true Protestant Religion with the Government Worship Discipline right and Privileges of this Church as above established by the Laws of this Kingdom in Prosecution of the Claim of Right
The new Sovereign must also take an oath relating to the Church of England, but that is done in the presence of Parliament on the first State Opening following the monarch's accession to the Throne. This oath, known as the Accession Declaration, runs as follows:
- I, N, do solemnly and sincerely in the presence of God, profess, testify and declare that I am a faithful Protestant, and that I will, according to the true intent of the enactments to secure the Protestant Succession to the Throne of my realm, uphold and maintain such enactments to the best of my power.
This preceding oath—first taken by George V in 1910—is a moderated version of the oath below which had been taken by every English and British monarch since William and Mary in 1689 until Edward VII in 1901, and which, by the early 20th century, was deemed too overtly anti-Catholic:
- I, N, profess, testify, and declare, that I do believe that in the Sacrament of the Lord's Supper there is not any Transubstantiation of the elements of bread and wine into the Body and Blood of Christ at or after the consecration thereof by any person whatsoever: and that the invocation or adoration of the Virgin Mary or any other Saint, and the Sacrifice of the Mass, as they are now used in the Church of Rome, are superstitious and idolatrous. And I do solemnly in the presence of God profess, testify, and declare that I do make this declaration, and every part thereof, in the plain and ordinary sense of the words read unto me, as they are commonly understood by English Protestants, without any such dispensation from any person or authority or person whatsoever, or without thinking that I am or can be acquitted before God or man, or absolved of this declaration or any part thereof, although the Pope, or any other person or persons, or power whatsoever, should dispense with or annul the same or declare that it was null and void from the beginning.
This oath was originally required by the Test Acts to be taken by all members of either house of Parliament, and all civil and military officers. However, following Catholic Emancipation, it later came to be taken only by the Monarch.
The King is dead. Long live the King! 
While "The King is dead. Long live the King" is commonly believed to be part of the official text of the Proclamation of Accession read out following the decision of the Accession Council as to the rightful heir to the throne, it is in fact only tradition that causes it to be recited immediately after the proclamation is read aloud in many villages and towns.