SUTTON, Chief Judge. The Internal Revenue Service, it’s often said, requires taxpayers to “turn square corners.” Rock Island, Ark. & La. R.R. Co. v. United States, 254 U.S. 141, 143 (1920). Complex statutes, book-length regulations, and too-many-part tests are an unfortunate reality of those turns. Yet the Internal Revenue Code, for all of the challenges of identifying taxable and non-taxable events before people act, still strives to make our nation’s tax system “accessible to everyone with the time and patience to pore over its provisions.” Summa Holdings, Inc. v. Comm’r, 848 F.3d 779, 781 (6th Cir. 2017). Congress and the citizens it represents prefer seen corners to unseen ones. In today’s case, the government seeks to impose a $39 million judgment, including interest and penalties, on Flight Options, a fractional-share jet company, for failing to collect a tax on fixed fees it charged to pay for the overhead and management of its clients’ private jets. The Internal Revenue Code imposes a 7.5% excise tax on the “amount paid for” domestic “transportation by air,” 26 U.S.C. §§ 4261(a), 4262(a)(1), what the statute called a “ticket tax” at all relevant times of this dispute, id. § 4261(e)(1)(C), (e)(5) (2012). The Code imposes the tax on the ticket buyer. But the Code makes the ticket seller liable for any tax it fails to collect on behalf of the government. Flight Options determined that the tax applies only to usage charges for each flight a client takes, not to fixed fees it charges its clients for overhead and management of its fractional jet business. The district court disagreed. It held that Flight Options should have collected taxes on the fixed fee charges as well and that, having failed to collect them, must pay the balance, with interest and penalties to boot. Because the ticket tax applies only to usage charges for each flight and not fixed charges for overhead and management costs, we reverse.