Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

Payroll reimbursments
As @Dilip suggested in the comments, the problem is the accountability of the reimbursement plans. In order for the reimbursement to be non-taxable, there has to be a reimbursement plan and policy set up by the employer, it has to be done per receipt, and accounted for correctly. If the employer just cuts you a check - the conditions may not be met, and as such - the reimbursement becomes taxable. In your case, it seems like the employer has not set up a proper (accountable) reimbursement plan, thus your reimbursements are taxable. @Joe pointed out that since the employer also doesn't withhold taxes (as he should), you may have an unexpected tax bill on April 15. This Chron article describes the distinction between the accountable and non-accountable plans. Only with the accountable plans the reimbursements are non-taxable.