Billy Mitchell (EastEnders) revealed in 2006 that the role was extended by "coincidence and chance": "I was offered four episodes and here I am, about 800 later. [...] Ross Kemp (Grant) said that he was leaving, and there was a gap in the Mitchell family, so they brought me back to do stuff towards his leaving. After that they offered me a year." Billy was reintroduced in 1999, making recurring appearances. He was involved in the leaving storyline of Grant Mitchell in October 1999, before returning later in the year as a regular character. When Billy was first introduced, he was depicted as
Grant Mitchell (EastEnders) return, Kemp commented, "When I was approached about returning to "EastEnders" for Barbara's final episodes, it was something I could not turn down. Barbara is a very close friend so when I learned of the storyline, it felt right that the Mitchell brothers are reunited with their mother for the last time. I am really looking forward to going back to "EastEnders" and filming what are set to be some classic "EastEnders" episodes." Kemp returned to filming on 6 April 2016. Later, it was announced that Kemp would film a further three weeks, and he resumed filming on 6 June