Jessopp had his best-ever Superbikes season in 2011 but a subsequent switch to World Supersport with PTR Honda did not go to plan.
A disappointing 2012 in pastures new failed to yield much success and the 27-year-old finished the season with only one point.
Jessopp will return to BSB for 2013, along with the RidersMotorcycles.com team, but this time will ride a BMW S1000RR rather than the Ducati twin.
"I have unfinished business in BSB and that is why I want to get back out there again,” he said.
“I think I took a year away at the wrong time in hindsight; at the time it was for the right reasons but I left when I was at my strongest position in the championship.
“It feels good to be back and on a competitive bike and everyone has seen that the BMW is a strong package in BSB. “I want to start the season and straight away pick up where we left off; there is no time to settle in and get comfortable but because I have raced the BMW before I don't think it will be an issue.
“We have the bikes stripped down at the moment and planning our test schedule so we can be ready for Brands Hatch. I want to be back up and fighting at the front and definitely pushing for the Showdown."