[14][15] In 2015, Tan achieved his first Grandmaster norm at the Colin Crouch Memorial Congress at Harrow, London.

[16] At the 2015 Under-18 World Youth Chess Championships in Greece, Tan tied for fourth place, after defeating GM Kirill Alekseenko.

[18][19] In the same year, Tan was joint winner with GM Luke McShane at the DeMontford Bell Kings Place Rapidplay.

[20] In 2018, Tan won the Paracin Open in Serbia, securing his final GM norm and the Grandmaster title.

[29] Tan was born and grew up in Cardiff, South Wales, United Kingdom, until the age of seven, when his family moved to Melbourne, Australia.