Nick Tilsley's current actor, Ben Price, is ten years older than his character's age.
While Sunita Alahan was born in 1978, Shobna Gulati was born in 1966.
Helen Worth who plays Gail was born in early 1951 while the character was born in 1958. To contrast, Gail's Mother Audrey is three years older than her actress Sue Nicholls (born late 1943). In other words, there is only a seven year age difference in real life between onscreen mother and daughter.
19-year-old Lucy Fallon started playing 14-year-old Bethany Platt in 2015. The heavy amount of make-up that Bethany liked to wear made the age difference very noticeable. Also worth noting that Bethany was originally going to be played by Katie Redford who was 25 years old at the time.
Fake Irish: A borderline example with the Connor family. While Michelle, Liam and Paul were presumably reared in England, they were born to Irish parents and seem to have kept close contact with Ireland (their parents returned to Dublin to live). Of the three, only the actor playing Paul had any known Irish ancestry and even his parents were English-born.
Tracy Barlow. Played by various actors, with Dawn Acton and Kate Ford being two of the best-known.
Tracy's step-brother Peter has been played by seven different actors. Two have even appeared as completely different characters including Ken's other son.
Tracy's daughter Amy holds the show's record of the most actors to play a character with a total of eight actresses. Most of these actresses however, were babies or toddlers at the time and weren't even old enough to read lines or really understand what was going on.
Most of the characters introduced as children.
Nick Tilsley. Twice, and both times as an adult.
Averted with Chesney Brown — Sam Aston has played the character from a child to an adult.
Post-Script Season: Probably the ultimate example — it has essentially been on a series of postscript seasons since 1961. It was originally intended to be thirteen episodes long, with Coronation Street bulldozed in a Made-for-TV Movie. However, it proved so popular that a new series was commissioned, and it's been broadcasting more or less continuously to the present day.
Averted with William Roache (Ken Barlow) & Michael LeVell (Kevin Webster) - both characters were written off the show whilst their actors were awaiting trial for sexual offences. Both actors were found not guilty, allowing the show to bring them back to the show.
Bruce Jones (Les Battersby) was written out after allegations of drunkenness and inappropriate comments in the presence of an undercover reporter.
Chris Fountain (Tommy Duckworth) was abruptly fired after a homemade rap video where he sang about rape was discovered online.
Marc Anwar (Sharif Nazir) was dropped from the show in September 2016 after making negative comments about India (as Anwar was born in neighboring country Pakistan) on Twitter. The actor alleged that his contract was going to be up soon anyway, so was only dismissed early; either way he was dropped earlier than expected.
Katie Redford (Bethany Platt) before she even started filming her first episode. She was fired from the role when fans on the Digital Spy forum uncovered evidence that she had lied about her age. She was replaced with Lucy Fallon.
Tina O'Brien (Sarah Louise Platt) dated Bruno Langley (Todd Grimshaw), the couple splitting up before their characters began dating.
She then began dating Ryan Thomas, who plays Jason Grimshaw, Todd's brother and Sarah Louise's future husband.
A more successful pairing is between Alan Halsall, who plays Tyrone Dobbs, and former Corrie actress Lucy-Jo Hudson, who played Katy Harris from 2002-2005, who have been married since 2009 and welcomed a baby girl four years later.
Upon both Tracy and Peter's returns in the early 2000s, there were talks for them to become involved with one another and Tracy to become pregnant as a result of the affair. This, thankfully, never came about, due to some very obvious reasons.
Also, there was supposed to be a conclusion to the Maya Sharma storyline involving a trial against her, but was left unresolved due to some personal reasons involving Jimmi Harkishin, who plays Dev Alahan.