Spurs initially brought Tel to North London on loan in early February for a fee of €10 million, with the agreement including a €35 million purchase option.
The young striker managed two goals and one assist in 13 Premier League appearances, mostly coming off the bench.
Tottenham set to permanent Tel's deal
According to Bild, Tottenham have decided to activate Tel's clause to permanently bring him to the Premier League.
This move comes just days after the appointment of new Tottenham manager Thomas Frank, who likely endorsed the decision.
Considered a top prospect from Bayern's academy, Tel struggled to break into the first team, which limited his playing time.
However, he is set to get another chance to kickstart his career as a youngster, with Spurs taking a risk to bring him to England.