On 1 June 2016, Internazionale announced the signing of Erkin on a free transfer in a three-year deal commencing on 1 July. Erkin was the first summer transfer addition to the squad. Under Roberto Mancini and new coach Frank de Boer, Erkin made 7 appearances in pre-season friendlies. However, he did not make any competitive debut before leaving Inter on 30 August. Inter also ran out of players quota in 2016–17 UEFA Europa League, as the club was forced to reduce to 22-men squad (plus normal minimum requirement of homegrown and club-trained players) due to penalty of UEFA Financial Fair Play Regulations, thus Caner was sacrificed for other signings. Domestically, Inter had one quota left (plus another for an Inter-trained player), but left vacant.
On 30 August 2016, Internazionale announced that Erkin's one-year deal with his homeland club Beşiktaş as on loan. On 7 June 2017, Beşiktaş signed Erkin for €750,000 transfer fee.