HARRY and Meghans attempt to trademark their Sussex Royal brand has been blocked after a complaint from a man in Australia.
The pair are keen to use the name to launch their foundation and make money from branded goods including hoodies and postcards.
The Queen has yet to decide whether they can still use the royal part of their name.
And now they face a legal battle after an Aussie doctor launched a legal opposition to the trademark.
Documents at the Governments Intellectual Property Office show that a formal notice of threatened opposition has been registered, this week.
The notice was sent on Tuesday and means Harry and Meghan could have to shell out in lawyers fees and other costs to get the right to use the name in the UK.
After registering a trademark, there is a period of opposition, when anyone against its use is first allowed to make this known and has the effect of extending the time before the trademark can be used.
Delayed application by at least one month
It gives opponents the time to mount a case against its use, although they may decide not to object.
The period of opposition for Harry and Meghans application was due to end on February 20, but that period is now extended until at least March 20.
The opposition was filed by Benjamin Worcester of Victoria, Australia, who is believed to have worked as a doctor in the NHS in London from 2011 to 2014 and studied medicine at University College London.
It is not known why he filed the opposition.
Lee Curtis, a chartered trademark attorney and partner at specialist law firm HGF, said : Filing a notice of threatened opposition is relatively easy and can be done online for free.
The filing of a formal notice of opposition is much more involved.
Right now, the threatened opposition delays the progress of the Sussex Royal application by at least one month, but if a formal opposition is ultimately mounted, this will involve the payment of an opposition fee, the drafting of formal grounds of opposition and the filing of evidence and legal submissions in support of the opposition.
The whole opposition could take at least a year to get to a decision and is thus not an action entered into lightly with a possible costs award against the losing party.
A spokeswoman for the Intellectual Property Office said last night: We are unable to discuss specifics about trade mark applications while they are in progress.
