In the United Kingdom, Counsellors of State are senior members of the British Royal Family to whom the monarch, currently Elizabeth II, delegates certain state functions and powers when not in the United Kingdom or unavailable for other reasons (such as short-term incapacity or sickness). Any two Counsellors of State may preside over Privy Council meetings, sign state documents, or receive the credentials of new ambassadors to the United Kingdom of Great Britain and Northern Ireland.
While the establishment of a regency carries with it the suspension of the monarch from the personal discharge of the royal functions, when Counsellors of State are appointed, both the sovereign and the counsellors can—the Counsellors within the limits of their delegation of authority—discharge the royal functions. Thus, the monarch can give instructions to the Counsellors of State or even personally discharge a certain royal prerogative when the counsellors are in place. The Counsellors of State and regents always act in the name and on behalf of the sovereign.
The Counsellors of State do not assume the discharge of the royal functions automatically when the sovereign is unavailable. Instead, when an instance of travel abroad or temporary unavailability occurs, the monarch must sign specific letters patent delegating the royal functions (or some of the royal functions) to the Counsellors of State and fixing the duration of the delegation. The monarch may at any time amend or revoke the said letters patent.
The first Counsellors of State were created in 1911 by an Order in Council of George V, and this process was repeated on each occasion of the King's absence or incapacity. The Regency Act 1937 established in law those individuals that could serve as Counsellors of State. The Counsellors of State are the of the monarch and the first four people in the line of succession who meet the qualifications. These qualifications are the same as those for a regent: they must be at least 21 years old (except the heir-apparent or presumptive, who need only be 18 years old), they must be domiciled in Britain, and they must be a British subject. One exception was made for Queen Elizabeth The Queen Mother (see below).