Chargebee, a startup that helps businesses with subscription billing and revenue management, has become a unicorn after raising $125 million at a valuation of $1.4 billion. The new financing round was led by Tiger Global, Insight Venture Partners and Sapphire Ventures. Chargebee was founded in 2011 in Chennai by Krish Subramanian, Rajaraman Santhanam, Saravanan KP and Thiyagarajan T.