When should the Union flag be flown at half mast?

The Union Jack flag at Whitehall is flown at half mast following the death of Queen Elizabeth II.

Flag lowered to half-mast at Windsor Castle after Queen Elizabeth II's death

users have claimed that Union Flags are flying at half-mast outside

Downing Street Union Jack at half-mast after death of Queen Elizabeth II | AFP

EU flag sales in UK at half mast after Brexit vote

Government Buildings to Fly Union Flag All Year | NTD UK News

Are Union Flags flying at half-mast across UK? As netizens worry for Kate and Charles

British flag removed from EU Council building

Gulf War veteran has been ordered to take down Union Jack flag

Flag at half-mast over the UK parliament

Union flags fly at half mast in tribute to the late Duke of Edinburgh | SWNS

UK lowers flag to half mast in memory of Tunisian shooting victims

Union Jack at Buckingham Palace at half-mast after death of Queen Elizabeth II | AFP

Flags to fly at half mast until morning after Queen’s funeral

Union flag taken down outside EU Council building in Brussels

Kate Middleton drama: Flags at #Buckingham Palace were not recently flown at half-mast #royal #uk

Union Jack at half mast at the Tower of London and bell being tolled 96 times on Fri 9th Sept 2022

EU flags placed at half-mast across the European Union following the passing of Queen Elizabeth II

UK flag lowered at Buckingham Palace to mark the death of Queen Elizabeth II