On 11 June 2011 it was announced that Johnny Menyongar would leave the club to join I-League team Shillong Lajong as well as Indian internationals Renedy Singh and NS Manju in January 2012.

[4] The club then went on to win three more matches during the first round of the I-League 2nd Division against Eagles, Southern Samity, and Ar-Hima in order to qualify for the 2012 I-League 2nd Division final round in which the club won promotion on the last day of the season on 17 April 2012 at the Paljor Stadium in Gangtok, Sikkim in front of 30,000 fans as United Sikkim drew Mohammedan 1–1 with Daniel Bedemi scoring the goal for United Sikkim.

[5] United Sikkim entered the 2012 Indian Federation Cup automatically following promotion to the I-League.

They were placed in Group D along with Salgaocar, Pune, and Prayag United and their matches were played in Jamshedpur.

[18] The tournament did not end well for United Sikkim as they lost all three of their matches, finishing with 0 points, 0 goals scored and 6 conceded.