Wesleyan has raised £250,000 for its chosen charity the Birmingham Children's Hospital, with the money going to the new Children's Cancer Centre.
The mutual began raising money for the Birmingham Children's Hospital in January 2013, and has since extended the partnership and doubled the original fundraising target.
Liz McKenzie, group corporate services director and chair of the Charity Advisory Committee at Wesleyan, said: "This £250,000 is the largest amount Wesleyan has ever raised for one of its chosen charities.
"Our staff have given both their time and their money generously over the past two years, getting involved in a whole range of activities, from abseiling down our head office building to giving up Christmas Day to deliver presents to the children in hospital.
"Those who have visited Birmingham Children's Hospital to see where their donations have been spent have been really moved by the experience and it has spurred them on to do even more.
"We can't wait to start our next round of fundraising activities and have big plans for the years ahead."
Elinor Eustace, corporate partnerships manager at Birmingham Children's Hospital, said: "Wesleyan is our largest corporate supporter and for it to raise such a large amount of money in such a short space of time is a fantastic achievement.
"To know we have its support for another two years is great news and will make a huge difference to the lives of our brave children and their families as we continue our plans to improve our facilities - enabling us to treat even more children from the West Midlands and around the country."