City and County of Denver v. Expedia, Inc, 2017 CO 32

Denver issued notices assessing unpaid lodger’s tax, interest, and penalties (2001–2010) against Expedia and other online travel companies (OTCs) based on merchant-model transactions.
OTCs operate two models: an agency model (hotels set price; hotels collect/remit tax) and a merchant model (OTCs set retail price, collect payment and a tax surcharge, remit a net rate + surcharge to hotels).
Hearing officer found OTCs in merchant-model transactions were "vendors" under the Denver lodger’s tax ordinance and that OTC markups/service fees were "directly connected with" furnishing lodging; he upheld Denver’s assessments (except fraud penalties).
The district court largely affirmed but limited liability by statute-of-limitations; the court of appeals reversed, finding ambiguity and construing the ordinance for taxpayers, vacating assessments as to OTCs.
Colorado Supreme Court reversed the court of appeals: it held OTCs are vendors and their markups are part of the taxable purchase price; the case was remanded for remaining issues (e.g., statute of limitations and amounts).

Issue	Plaintiff's Argument (Denver)	Defendant's Argument (OTCs)	Held
Whether OTCs in merchant-model transactions are "vendors" required to collect/remit Denver’s lodger’s tax	OTCs functionally sell the right to occupy rooms: they set retail price, collect payment, add tax surcharge, and contractually obligate hotels to provide rooms—thus they are vendors.	OTCs are intermediaries/agents or resellers who do not "furnish" rooms; hotels furnish lodging and should remain the vendors responsible for tax collection.	OTCs are vendors: "furnishing" means making a sale of the right to overnight use; merchant-model OTCs sell that right, collect payment, and therefore must collect/remit the tax.
Whether OTC markups and service fees are included in the "purchase price paid or charged" taxable base	Markups and bundled fees are inseparable from the selling price the OTC charges; if OTC is the vendor, the taxable base includes amounts without which the OTC will not sell the reservation.	Markups and service fees compensate for online facilitation and are not "directly connected with" furnishing lodging and therefore should be excluded from taxable lodging price.	Markups/service fees are included: if inseparable from the sale price and the purchaser must pay them to acquire the lodging, they are "directly connected with and included in the price" and are taxable.

Taniguchi v. Kan. Pac. Saipan, Ltd., 566 U.S. 560 (interpret undefined terms by ordinary meaning and context)
United States v. Ron Pair Enters., Inc., 489 U.S. 235 (punctuation can confirm statutory meaning but is not dispositive)
Apollo Stereo Music Co. v. City of Aurora, 871 P.2d 1206 (taxation focuses on substance over form; functional criteria control vendor status)
Beeghly v. Mack, 20 P.3d 610 (inclusion/exclusion in statutory lists informs interpretation)
Welby Gardens v. Adams Cty. Bd. of Equalization, 71 P.3d 992 (tax statutes must be construed harmoniously within statutory scheme)
People v. Thoro Prods. Co., 70 P.3d 1188 (rule of lenity and tax presumptions are rules of last resort in statutory construction)