Their characters Bianca Butcher and Carol Jackson will be back as Walford regulars in time for the Christmas period, The Sun reports.
Digital Spy can also confirm that Carol and the Butcher children will return to Albert Square for a week from October 29, before making their permanent return with Bianca a few weeks later.
"The cast and crew are excited that the Jackson family are due to return and their storylines are as colourful as ever," an insider told the paper, saying that Bianca and her children would have "a heavy screen presence over the festive period".
"Bosses are hoping the return of Bianca and Carol will prove a big draw for viewers over Christmas," the source added, confirming that Bianca is due to return to screens as her uncle Max Branning remarries ex-wife Tanya on Christmas Eve.
Palmer took a break from the soap earlier this year to spend time with her family.
Viewers saw Bianca leave Walford as she breached the terms of her probation by attempting to steal money from a market stall, as she faced extreme financial hardship.
Carol followed her daughter out of the soap, moving to Suffolk temporarily with Bianca's children.
Watch Bianca's EastEnders character trail below: