[2] Yapp Hung Fai started his professional career at Workable when he was only 17 under coach Lee Kin Wo and Chan Hiu Ming in 2007.

[4] During his time at Workable FC, he helped the team to an unexpected 1:0 win against South China AA in the 2007-08 Hong Kong League Cup.

On 29 September 2010, during Tottenham Hotspur's chief scout Ian Broomfield's visit to South China, he praised Yapp for his enormous potential.

"[7] After defeating East Bengal in the 2011 AFC Cup game at home on 14 April 2011, South China striker Mateja Kezman suggested that Yapp Hung Fai has what it takes to play in European football leagues.

[10] On 11 February 2010, at the age of 19, Yapp made his senior debut for Hong Kong in a 2010 East Asian Football Championship match against Japan.

On 8 December 2024, Yapp got his 100th cap for the national team after playing against Mongolia in a 2025 EAFF E-1 Football Championship Preliminary Round match.

South China Pegasus Eastern Hong Kong U-23 As of 14 May 2023[13] Yapp has excellent speed and reflexes, making him an ideal one-on-one goalkeeper.