Square doubles in size in a year; now boasts 600 employees

In 2012 Square had 300 employees, but as of today that number has blossomed into 600. That forced the mobile payments startup to move out of its cramped offices in the San Francisco Chronicle building and into new 150,000-square-foot digs in SF’s Central Market district. The new HQ officially opened for business this week.

The rapid growth comes as Square expands beyond its original smartphone readers and payments software into other areas of commerce, including Stand, it’s sleek new merchant point-of-sale system, and Market, Square’s bid to become an online commerce player. And those are just the new products that are commercially available. Square is getting ready to take on PayPal(s ebay) with a new peer-to-peer transactions service. Square co-founder and CEO Jack Dorsey will be speaking at GigaOM’s Roadmap conference in November.

Consequently Square has staffed up quickly and it’s opening offices outside of the Bay Area. It said it has already signed deals to expand its square footage in New York City’s Soho neighborhood, making it a key engineering facility. It also plans in 2014 to open up offices in Waterloo, Canada, it’s first permanent venture north of the U.S. border. In addition to SF and NYC, Square currently has offices in Tokyo and Atlanta.