The new figure is the third time the company has updated it volume forecasts for 2011. At an analysts day in February, the company upped its projections to $2 billion, from the $1.5 billion anticipated last Autumn.
Presenting the new figures, Laura Chambers, senior director PayPal Mobile, says: "Mobile payments are growing at a rate we never could have imagined when we started processing them back in 2006."
She says the company is now seeing up to $10 million in mobile transaction processing volume a day - a sharp incline from the $6 million reported in March.
"We currently have eight million customers who are regularly making purchases on their mobile phones, up from a previously reported six million users," says Chambers.
The latest growth projections come at a time of booming commercial investment in mobile commerce and payments.
Speaking at Cannes, Wednesday, Eric Schmidt, Google's executive chairman, said he expected that up to a third of eftpos terminals in the US would be capable of processing mobile payments within the year, spawning a "trillion dollar industry".