After the attack on the Paris offices of Charlie Hebdo, the French government has declared Thursday 8 January as a national day of mourning for the twelve victims.
This will be only France’s sixth national day of mourning in the past 50 years.
In the UK you may fly the national flag at half-mast whenever you feel it is appropriate.
You may also fly the French national flag at half-mast.
If you do so alongside a UK national flag, the latter must also be at half-mast or removed.
Any other national flags should be removed.
Special provisions apply where a flag cannot fly at half-mast; for example, if it is on an angled pole projecting from a building.
Here you may add a black cravat or ribbon to the top of the flag, closest to the flag pole.
For full guidance on flying flags at half-mast, see Flying Flags in the United Kingdom, free to download here.

