When should the Union flag be flown at half mast?

Half Staff Flags Explained | Flag Facts

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

Why Do We Fly Flags Half Mast or at Half-Staff?

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

Union Flag at half-mast.

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

When to Fly the US Flag at Half Staff

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

UK vs USA - American flags that include the British Union Jack

American regions that still have a Union Jack 🇬🇧

Flags At Half Mast Over London (1941)

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

Did you know this was ALMOST the union flag? 🤯 🇬🇧 #Union with David Olusoga #iPlayer

EU flag sales in UK at half mast after Brexit vote

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

Flag at half-mast over the UK parliament