The source added: “They have thought about this carefully and have researched it very well.
“This is the place where they plan to be happy, make good friends and bring up Archie, giving him the chancer to play with other children his age.”
The Sussexes are believed to have chosen a property in the exclusive hill-top area of Montecito, which is home to celebrities including Oprah Winfrey and Ellen DeGeneres.
Last month, before it was known the couple were going to make the move to Santa Barbara, it was reported Meghan had chosen the area to spend her 39th birthday on August 4.
Montecito is described by one luxury estate agent as “a paradise for Hollywood stars and the super rich who want to live in splendid isolation”.