In 2015, Smart moved to the United States, taking up the role as assistant professional at the Tennis and Racquet Club in Boston.

At the start of 2016, he won the British Under 24 Open against Ed Kay at his alma mater of Middlesex University.

Once play had returned to normal in 2022, Smart had his best season yet, defeating top 10 player Chris Chapman in the quarter final of the 2022 US Open at his home court in Tuxedo.

In doubles, he reached the semi final stage at both the French and US Opens partnering with Chapman and Darren Long respectively.

At the end of the season, he moved back to the Tennis and Racquet Club, this time as head professional.

He also reached his second doubles final at the same event, partnered with Steve Virgona but losing to Nick Howell and Camden Riviere.