The actress was dropped from the BBC One drama in April last year after producers apparently decided that her character Honey Mitchell had "come to the end of her storyline". She has since secured the lead part of Roxie Hart in a touring production of Chicago.
Barton's last scenes on the soap saw Honey leaving Walford with her son William and daughter Janet following the breakdown of her marriage to Billy (Perry Fenwick).
Reflecting on her departure, Barton told the Sheffield Telegraph: "I came to the end of my contract and the executive producer decided there wasn't much more to do with the character of Honey.
"I think having to leave was a blessing in disguise rather than playing a part that couldn't do much more and running the risk of getting tied to it."
She continued: "I am a great believer that everything is meant to be for a reason and I am grateful for what I am doing now.
"I left in a cab so I guess the door remains open but I can't see me going back."
Barton has previously suggested that Honey was written out too hastily.