Square, a Mobile payments startup, announced this morning that it has raised $100 million in Series C financing which puts its valuation close $1 billion according to the Wall Street Journal. The funding round was led by high-profile venture capital firm Kleiner Perkins Caufield & Byers.

The company Tweeted today:”To continue to empower everyone to accept payments anywhere, we’ve raised $100 million in our Series C Financing, led by @kpcb”.

Square, created by Twitter co-founder Jack Dorsey in 2009 who serves as its CEO, allows small businesses to use smartphones to process credit card payments. The platform processes payments using a small, square-shaped credit card reader that plugs into the iPhone, iPad or Android-based devices.

The mobile payment sector is hot and analysts have expressed caution on Square, because it is operating in the highly competitive market of mobile payments. Google recently teamed up with MasterCard, Citigroup , and Sprint to launch a new phone-based mobile payment system. Ebay’s Paypal, wireless carriers and several banking giants are also a big player in that space.

The company is trying to broaden its appeal by targeting various pain points in payments processing. Square recently launched An iPad app aimed at replacing cash registers which lets customers pay with their Android or iOS devices.

Kleiner Perkins Caufield & Byers has backed several notable companies in the tech space, including Amazon.com, Google and Electronic Arts (EA). The venture capital firm also has a fund dedicated to iOS developers.