The two parties eventually reached an agreement where he would be available for the group stages of the competition, but his participation was not guaranteed if England progressed to the knock out rounds. Having signed a new contract keeping him at the club until 2022, [29] Sancho enjoyed a successful October 2018 by being named Bundesliga Player of the Month, registering three goals and an assist in just three league games. Coming on as a substitute for Brereton, Sancho scored the last of the goals in England's 4–1 win over Hungary in the first match of the elite round on 21 March 2018. During a 3–3 draw with 1899 Hoffenheim on 9 February 2019, he became the youngest-ever player to score eight goals in a single Bundesliga season, breaking the record previously held by Christian Wück. On 23 November, he scored his first goal for the club, against Villarreal to secure a spot in the knockout stage of the Champions League.

In response, Sancho wrote on social media that "I will not allow people saying things that is completely untrue, I have conducted myself very well in training this week. Finance is provided by PayPal Credit (a trading name of PayPal UK Ltd, Whittaker House, Whittaker Avenue, Richmond-Upon-Thames, Surrey, United Kingdom, TW9 1EH).Most purchases from business sellers are protected by the Consumer Contract Regulations 2013 which give you the right to cancel the purchase within 14 days after the day you receive the item. Success continued ahead of the 2019–20 season, with Sancho providing an assist and scoring in a 2–0 DFL-Supercup victory over Bayern Munich on 3 August 2019.

From Christian Pulisic to Erling Haaland via Jadon Sancho: why do Borusdia Dortmund attract the game's best young players? During the September internationals, Sancho scored his debut goals for the senior team, a brace, in a 5–3 home victory over Kosovo in a Euro 2020 qualifier on 10 September.

Trading Card of Jadon Sancho from Golden Baller series of the Manchester United team with number 7 from official collection Panini Adrenalyn XL Premier League 22/23. On 13 January, Sancho featured in his first match since rejoining Dortmund, coming on as a substitute in the 55th minute of the game against Darmstadt 98, which ended in a 3–0 win, with Sancho providing the assist for a goal from Marco Reus. Sancho's three goals and three assists in five league matches during February 2020 saw him named Bundesliga Player of the Month for the second time in his career. Sancho continued to impress in the City academy and was one of a trio of players that City chairman, Khaldoon Al Mubarak, said would be fast tracked into the senior set up in May 2017. He later stated that he felt confident in making the move abroad due to his previous experiences in relocating with Watford and Manchester City.

He took England's fourth penalty in the subsequent shoot-out, which was saved by Gianluigi Donnarumma. On 14 August, he made his debut as a substitute for Daniel James in a 5–1 home league win over rivals Leeds United. On 13 April, Sancho scored a brace in a 2–1 win over Mainz 05 and in doing so became the youngest-ever Dortmund player to score at least 10 goals in a single Bundesliga campaign.Later that month, upon scoring in a 3–2 win over Bayer Leverkusen, he broke Lukas Podolski's record to become the youngest player to score nine Bundesliga goals, aged 18 years and 336 days.