The lawsuit claims that Rowling's fourth novel Harry Potter and the Goblet of Fire is "substantially similar" to Jacobs's 1987 book The Adventures of Willy The Wizard. Earlier this year, the estate said that it would "vigorously pursue" the case in the UK, following a US courts decision to dismiss it.
The Daily Mail reports that at a hearing in the Chancery Division of the High Court, Mr Justice Kitchen told Allen that he would have made the security payments for 65% of the costs incurred by Rowling and her publisher Bloomsbury.
By April 21, he will have to pay £322,691 towards Bloomsbury's costs and £571,613 for Rowling's, followed by £24,650 and £178,441 for the publisher and author respectively by August 5.
The judge warned that the ten-day trial, currently scheduled for February next year, would not go ahead if the payments were not made.
The estate had previously been told that it was "improbable" that the allegations against Rowling would succeed in court.
> Publisher denies Harry Potter plagiarism