Comments by CEO suggest payments firm in ready to expand outside the US.
Square has a good claim to being the most hyped mobile start-up in the world right now. Its credit card dongle, which turns any smartphone or tablet into a payments processor, has around two million users.
It also offers the Pay By Square service which enables a user to ping a merchant ahead of arrival and say their name to complete the transaction.
The firm reckons its transactions value is now on target to hit $6 billion this year.