Travel expense reimbursements billed as subsistence, per diem, and accommodation reimbursements are not subject to sales tax since this re-billing occurs after the actual taxing event. These travel expenses are taxable when incurred by the company from the vendor; e.g. airline ticket counter, rental car company, hotel, or restaurant, etc. Separately-stated mileage charges are also exempt from sales tax. Specifically exempted charges associated with a retail sale/service are as follows: intrastate transportation of employees to/from a work site when paid or contracted for by the employer or employee, intrastate transportation of freight, and interstate transportation of persons and freight. Also please note that Wyoming Department of Revenue Rules, Chapter 2, Section 9(a) requires non-taxable items to be separate and distinguishable from taxable items or the entire invoice is taxable. (Sales Tax Bulletin #19 Wyoming Department of Revenue, August 1, 2008