ITV breached broadcasting rules with several of its viewer competitions, media watchdog Ofcom has ruled.
Some viewers who participated in competitions using a postal entry had "no chance of being selected to win", Ofcom said.
Competitions on shows like Good Morning Britain, Lorraine, This Morning, Loose Women and Ant and Dec's Saturday Night Takeaway were all involved.
More than 41,000 entries between 2016 and 2019 were affected.
Competitions on La Vuelta and X Factor: The Band were also found to be in breach of the broadcasting code.
ITV said it has put in place plans to improve its postal entry procedures and it intended to donate a sum of money to charity as a "mark of its sincere regret".
ITV investigated over competition entries
An Ofcom spokeswoman said: "Our investigation found that people who entered these competitions by post were excluded from the draw, with no chance of winning.
"ITV failed to follow proper procedures and this led to a clear breach of our rules, which require all broadcast competitions to be conducted fairly."
The broadcaster said the problem was a result of "human error by ITV staff" putting information on to a spreadsheet.