Do I have to repay my employer who incorrectly overpaid me?

How is it that you were unaware that you were continuing to receive the car allowance after you were transferred into the job that was not "car-elibile"?  Wasn't the item listed on your paycheck stub? Courts have allowed lawsuits to recover overpayments to employees.  It is not possible to say whether your employer could prevail in such a case against you without knowing more.  An employer may not withold amounts, including overpayments, from a Texas employee's paycheck without the employee's written permission.  Well-counseled employers may have some language in their initial employment documents (signed by the employee) which would permit such withholding.   However, even in that event, the employer may not withhold an amount which would cause the employee to earn less than minimum wage for each week included in the paycheck.  An employer would likely terminate an employee who refused to repay an overpayment.