Josephs, who turns turn 38 on May 19, entered into talks with Usuthu due to a lack of game-time at Wits this past season.
The former Orlando Pirates star made 10 appearances in 2017/18, as Students coach Gavin Hunt opted for Darren Keet as his first-choice keeper.
Josephs's contract with the Clever Boys is due to expire at the end of June.
“He signed a three-year deal at AmaZulu and his salary will be double of what he was getting at Wits,” a source tells this website.
“He was released [from Wits] because he couldn’t play.”
Josephs, who has won every domestic trophy on offer, will be expected to mentor and provide competition to AmaZulu keepers Siyabonga Mbatha, Energy Murambadoro and Neil Boshoff in Durban.