They have snapped up the 26-year-old German with a view to strengthening their squad for the Classics squad, having tracked him for several years.
"It’s great that this has finally worked out," said Bora-Hansgrohe team manager Ralph Denk.
We have been interested in Nils previously, that's certainly no secret. I think that the consistent path that Bora-Hansgrohe has been following was ultimately part of what convinced him.
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"As a German top team, we’d of course like to have all the top German riders under contract, but we are still looking for international talent. Our goal is not to become a German national team, but rather to win the WorldTour.
"Nils will of course be vital in strengthening our Classics squad, but we still also see a lot of potential in him generally as a rider."
Politt himself added: "I'm really very happy. In a way, it’s like being reunited with my friends from the early days, and that made the decision quite easy for me.
"I've known several of the riders in the team for a number of years and I'm looking forward to racing with them."
Politt's career highlight arguably came at the 2019 Paris-Roubaix, where he finished second.