The open casting call was confirmed by the studio to Variety on Tuesday after the announcement was published online by Cast It Talent.
Producers said they were looking for children living in the UK and Ireland who would be aged between nine and 11 in April next year.
The search for the heirs to Daniel Radcliffe, Emma Watson, Rupert Grint, and the rest of the stars of the original films "will be inclusive to all races, ethnicities and gender identities," they said.
Hopefuls must send two videos, with the first being "a short poem or story of your choosing" which can be taken from a "favourite book, a monologue of a play you love or something you've created yourself."
Daniel Radcliffe, Emma Watson, JK Rowling and Rupert Grint at the premiere Harry Potter and The Deathly Hallows: Part One in 2010. Pic: PA© PA
Recording on a phone is "great", but "please", the announcement said, "nothing from Harry Potter".
Candidates should use the second video to provide some personal details including "a bit about yourself", as well as date of birth, height, and where they live.
Plus, they must "describe any family member, friend or pet" they are "particularly close to".
The first should be no more than 30 seconds; the second a minute maximum and both should be in "your own accent".
The deadline for sending in the videos is 31 October.
JK Rowling published seven books about the boy wizard between 1997 and 2007, which were turned into eight films between 2001 and 2011.
The movies generated more than $7.7bn (£6.17bn) at the global box office.
When the new series was announced last year, Max, a streaming service from Warner Bros, promised it would "feature a new cast to lead a new generation of fandom, full of fantastic detail, much loved characters and dramatic locations that Harry Potter fans have loved for over 25 years".
The shows would be "authentic to the original books" with the films "at the core" of the franchise, Max said.
The seven Harry Potter books, published between 1997 and 2007, have sold more than 500 million copies worldwide.
