The Duke of Sussex will not be allowed to wear his military uniform to mourn the Queen, while his disgraced uncle Prince Andrew will sport his at the final vigil for Queen Elizabeth II at Westminster Hall.
Only working royals, which Harry and Andrew are not, will be allowed to dress in uniform at the ceremonies being held for the Queen.
Prince Andrew was stripped of his royal patronages and honorary military roles earlier this year after he faced sexual abuse allegations from a victim of convicted paedophile Jeffrey Epstein.
Meanwhile the Duke and Duchess of Sussex surrendered many of their titles after stepping back as senior members of the royal family to move to the US.
However in a shock decision, Prince Andrew will be allowed to wear the uniform of his armed forces "as a special mark of respect" for Queen Elizabeth.
But the Sun reports Prince Harry, who saw action on the front line during two tours of duty in Afghanistan, will be in civilian dress.
"No doubt a huge blow for the Duke of Sussex, who served for 10 years and this morning spoke of the Queen being his 'commander-in-chief'", tweeted journalist Omid Scobie, who covers the royal family.
According to Harper's Bazaar magazine, the decision on Harry's dress code could have been made by King Charles III, the Lord Chamberlain's Office, Queen Elizabeth II before her death, or a combination of people.