(1) Payments made by an employer to reimburse an employee for ordinary and necessary business expenses incurred during the course and scope of employment are not wages if the reimbursement amount:
(a) is entered separately in the employer's records;
(b) is not deducted from or based on a percentage of the employee's wage; and
(c) does not replace the customary wage for the occupation.
(2) Reimbursement must be based on:
(a) actual expenses for lodging, goods, or services incurred by the employee and supported by receipts;
(b) a flat rate for meals not exceeding the per diem allowed by the United States Internal Revenue Service for the year, unless, through documentation, the employer can substantiate a higher rate; or
(c) when an employee-furnished vehicle is used, a mileage rate no greater than that allowed by the United States Internal Revenue Service for that year.