CNBC reports that the Jack Dorsey-led company is seeking to gain around $200 million in funding, with part of that amount coming from the Government of Singapore Investment Corporation.
A recent valuation of $5 billion was reported earlier this year after investors bought shares from employees.
The fundraising round will come as welcome news for Square, which has found itself the subject of negative attention from the press recently.
The Wall Street Journal published a story in April claiming that Square's losses were so high that the company was scrambling to find a buyer. Despite denying these reports, Square's reputation was still dented, especially following the closure of its flagship Wallet app in May.
In a move that attempted to address the negative press attention, earlier this month Square published a blog post detailing 10 "negative myths" about the mobile payments company, a decision seen by many as needlessly defensive.
The new valuation will thus come as a rebuttal to the company's critics.
Square is facing increasing competition in the mobile payments market. Amazon recently launched a new card reader device that undercuts Square on transaction fees, while PayPal released its own system in 2012.