He will retain his minority shareholding, and said he would like to remain involved with the True Potential Foundation, to help promote charitable work.
However, he vowed not to turn up to AGMs and "ask annoying questions".
Nor will he have an entirely "clean break" as he will "see the kids from time to time", he joked.
"I've worked closely with Cinven for three years, and they are an excellent operator. They have taken the time to understand what we do as a business, and are hands-on, supportive and I see that continuing in the future. They also will keep me in the loop and update me from time to time."
Successor
According to Harrison, a successor has already been appointed. While their name is not yet able to be disclosed, Harrison said it was someone who is well known and experienced in the world of financial services.
Moreover, it is someone who, Harrison said, has a strong affinity to the culture of True Potential.
"He has agreed to relocate to Newcastle, to be present in the office. He struck me as a type of 'canteen general' - someone who believes in getting and among the troops, and working with the team that is already in place, rather than coming in and making sweeping changes.
"True Potential needs evolution, not revolution", Harrison said.
Jeff Casson, who is currently the chief investment officer, will be the interim CEO for the next few months until the new chief executive takes up the role in 2025.
"Jeff is fantastic", Harrison said. "He passes the test - which is that, if we cut his arm off, he would bleed purple. That is the culture test for us."
FT Adviser asked if the new CEO bleeds purple - the brand colour of True Potential - as well?
Harrison said: "He's external, so there may be some 'transplanting' done but he really gets what we do and what our culture is all about. So I believe he will."
Next steps
Harrison, who is now independently wealthy enough never to have to work again to earn a living, said: "I want to stay involved with the charities we've created - both at True Potential and our own family foundation.
"I was running through some stats that showed, since 2017, True Potential has given £25mn to charity - everything from classroom books to employment opportunities. I would like to continue to support these initiatives."
However, he also wants to spend time with family - his own father spends a lot of time in Antigua enjoying his retirement, and Daniel said he wants to be able to go and spend more time with his parents.
