Union Jack Union Jack The Union Jack, or Union Flag, is the national flag of the United Kingdom. The flag also has an official or semi-official status in some other Commonwealth realms: for example, it is a ceremonial flag in Canada by parliamentary resolution, and known there as the Royal Union Flag. Further, it is used as an official flag in some of the smaller British overseas territories. The Union Flag also appears in the canton (upper left-hand quarter) of the flags of several nations and territories that are former British possessions or dominions, as well as the state flag of Hawaii.
Flag of Northern Ireland state offices on specified 'named days' (honouring, for example Queen Elizabeth II's official birthday). The regulations also provides that, on the occasion of a visit to a government building by the British Monarch, the Royal Standard shall be flown and the Union Flag can be flown, and on state visits from other heads of state the Union Flag and the national flag of the country of the visitor can be flown. Where two flagpoles exist, the flag of Europe should be flown on Europe Day alongside the Union flag. The regulations prohibit any flags being flown from the relevant buildings