Competing in September 2016 at his first Junior Grand Prix (JGP) assignments, Phan placed sixth in Ostrava, Czech Republic, and fifth in Ljubljana, Slovenia.

In December, he won the senior men's event, ahead of Bennet Toman, at the Skate Canada Challenge and qualified to compete on the same level at the 2017 Canadian National Championships in January.

[9] Phan began his season in August at the 2017 Junior Grand Prix in Brisbane, Australia; he placed second in the short program, seventh in the free skate, and fourth overall.

In September, he won silver at his next JGP assignment, in Zagreb, Croatia, where he finished second to Alexei Krasnozhon of the United States.

Competing as a senior domestically, Phan finished first, ahead of Nicolas Nadeau and Nam Nguyen, in December at the Skate Canada Challenge.

Phan placed fourteenth in the short program, third in the free skate, and fourth overall at the 2018 World Junior Championships in Sofia, Bulgaria.

[12] In August 2018, it was confirmed that Phan had begun training under coach Brian Orser at the Toronto Cricket, Skating and Curling Club.

[17] Competing at Junior Worlds, Phan set a new personal best in the short program, despite putting a hand down on his triple Axel.

[22] Phan was assigned to make his Grand Prix debut at the 2020 Skate Canada International, but the event was cancelled as a result of the coronavirus pandemic.