The Digital Garage-backed communications platform closed an initial $35m in series C funding in August 2015, and has now added $50m in a C1 round.

Intercom, a US-based communications platform developer backed by internet company Digital Garage, raised $50m in series C1 funding today in a round led by venture capital firm Index Ventures.

Bessemer Venture Partners, Iconiq Capital and Social Capital also took part in the C1 round, which adds to the $35m initial series C close achieved in August 2015. The first tranche was led by Iconiq Capital and included Social Capital and Bessemer.

Founded in 2011, Intercom has created a platform through…