He took the job only in November, after joining the digital loans company in January 2013 as chief operating officer.
Wass took over from founder Errol Damelin, who stepped back to become chairman late last year.
Now Wass is out, and he is being replaced on an interim basis by chief finance officer Tim Weller, who has been with the company since 2012.
“My time with the company has been busy and productive, seeing Wonga launch in several new markets. But we’re now at the beginning of a new chapter and I felt the time was right to take a new opportunity elsewhere,” said Wass in a statement yesterday.
“There are some exceptional people here and Tim is inheriting a strong team.”
Wass is leaving in the coming weeks and is taking up an unspecified role at another company.
The payday lending industry is going through a major transition, as the Financial Conduct Authority has just taken over regulation of the sector. Since the watchdog took the reins, scores of payday lending brands have shut down, and others have had to update their debt collection practices as a new code of conduct has been brought in for the industry.
New interim boss Weller indicated yesterday that neither the turmoil at the top of the business, nor the tighter regulation, would prevent Wonga from continuing its ambitious plans to grow internationally.
“I’m looking forward to continuing my work with the great Wonga team. As we move to a new regulatory environment in the UK we are actively engaged with the FCA and committed to building better products for our customers,” he said in a statement yesterday. “We will also continue our expansion into new product areas and countries.”
Wonga itself has been a focus of the political criticism of short-term loans, as a high profile insurgent into British consumer lending.
However, the firm maintains it is a model of best practice for the industry as its loans cannot be rolled over several times, and the costs of borrowing are clearly outlined at the start of the process to apply for credit.