[1][2] After graduating from Tata Football Academy, Paul signed with I-League club Mohun Bagan in 2006.

He got to play his first match in an AFC Cup encounter]l. Since his debut, Shilton has been an integral part of the Mohun Bagan team every year.

Although an excellent goalkeeper, he sometimes got to play the second fiddle when the likes of Sangram Mukherjee, Sandip Nandy and Debjit Majumder were present in the team.

[6] After 14 seasons with Mohun Bagan, Paul joined Churchill Brothers in July 2020 for a one-year deal.

[7] He made his debut for Churchill Brothers in their 5–2 win over Indian Arrows in the 2020–21 edition of the I-League on 11 January 2021.