Following the death of The Duke of Edinburgh, flags have been half-masted at all Royal Residences flying the Union Flag.

When The Queen is in residence the Royal Standard is flown. Unlike the Union flag, the Royal Standard is never flown at half-mast.

Instructions for the flying of flags on Government buildings and military establishments have been issued by the Department for Digital, Culture, Media and Sport: https://www.gov.uk/government/news/death-of-his-royal-highness-the-duke…