New Jersey is the latest state to say Uber's drivers should be classified as employees rather than independent contractors.
The state's Department of Labor and Workforce Development said that because of this misclassification, the ride-hailing company owes it roughly $650 million in unemployment taxes and disability insurance, according to Bloomberg Law.
The Department of Labor reportedly has been trying to get unpaid employment taxes from Uber going back as far as 2015, according to documents obtained by Bloomberg Law.
It said the company owed the state $523 million in overdue taxes along with another $119 million in interest and penalties for the last four years.
Driver classification is an issue that government regulators have been taking a closer look at over the past year.
California passed a law in September that could require Uber and other on-demand companies to reclassify their drivers as employees instead of independent contractors.