Cylinder rental fees charged by a seller of industrial, medical, and welding gasses were subject to Wyoming sales tax since the seller failed to establish that the rental fees were exempt as demurrage charges. Wyoming regulations provide that demurrage charges made by vendors selling acetylene, oxygen, nitrogen, helium, and similar gaseous products in returnable containers are not subject to sales tax. The taxpayer argued that its cylinder rental fee is exempt demurrage since it works like a penalty to incentivize quick return of its cylinders. The Board of Equalization noted that demurrage charges arise from an agreement between the parties. The board stated that no evidence was provided that the taxpayer and its customers entered into a demurrage arrangement, even if the taxpayer’s rental terms share some of the characteristics of traditional demurrage. The taxpayer additionally contended that the Department of Revenue abused its discretion by imposing (or by not waiving) interest for the period of 2015-17 since the Department didn’t publicize its interpretation of the demurrage rule until 2018. The Department noted that it “does not have a duty to provide unsolicited interpretations to taxpayers.” Based on all of the above, the taxpayer’s cylinder rental fees were properly subject to tax and interest. (Airgas USA LLC v. Wyoming Department of Revenue, Wyoming State Board of Equalization, No. 2019-23, March 19, 2020)