Utah Code § 10-1-306

(1) The delivered value of taxable energy under this part shall be established pursuant to rules made by the commission in accordance with Title 63G, Chapter 3, Utah Administrative Rulemaking Act. (2) The rules made by the commission under Subsection (1): (a) shall provide that an arm's length sales price for taxable energy sold or used by a taxpayer in the municipality is the delivered value, unless the sales price does not include some portion of the taxable energy or component of delivered value; (b) shall establish one or more default methods for determining the delivered value for each customer class one time per calendar year on or before January 31 for taxable energy when the commission determines that the sales price does not accurately reflect delivered value; and (c) shall provide that for purposes of determining the point of sale or use of taxable energy the location of the meter is normally the point of sale or use unless the taxpayer demonstrates that the use is not in a municipality imposing the municipal energy sales and use tax. (3) In establishing a default method under Subsection (2)(b), the commission: (a) shall take into account quantity discounts and other reductions or increases in value that are generally available in the marketplace for various grades or types of property and classes of services; and (b) may consider: (i) generally applicable tariffs for various classes of utility services approved by the Public Service Commission or other governmental entity; (ii) posted prices; (iii) spot-market prices; (iv) trade publications; (v) market data; and (vi) other information and data prescribed by the commission.