The country's two largest convenience-store chains — 7-Eleven (12,000+ stores) and Circle K (7,300 stores) — systematically charge customers more at the register than the price posted on the shelf. A Guardian investigation drawing on government inspection data, consumer complaints, and interviews reveals failure rates that would be scandalous in any other retail sector: Circle K failed 82% of price inspections in Columbus, Ohio, and 62% in North Carolina between 2023 and 2025. 7-Eleven failed 79% in Ontario County, New York, and 47% in both Colorado and Utah. A single 7-Eleven in Casa Grande, Arizona, rang up 12 of 25 sampled items above shelf price — a 48% error rate on everything from KitKats to pickle snacks. The overcharges are individually small — a dime on Pickle Bites, a dollar on gum — but they compound across a customer base of staggering size. Up to 57% of Americans shop at convenience stores at least once a week, according to the National Association of Convenience Stores. When the markup is systematic and the customer is grabbing a snack at 1am, the information asymmetry is total. The shelf price is a promise; the register is where the promise breaks. Convenience stores are the worst-performing retail category in America for price accuracy. A 2024 National Council on Weights and Measures report found they failed 34% of price inspections across 26 states, worse than dollar stores (29%) and auto parts stores (27%). This is not a rounding error or a staffing glitch. It is a structural feature of a business model that depends on distracted, time-pressed customers who rarely check receipts and have no practical recourse when they do. Regulatory oversight is nearly nonexistent. Texas, home to 16,500 convenience stores — more than any state — conducted just 32 inspections of 7-Eleven and Circle K locations over three years, despite receiving 51 consumer complaints. Arizona has 14 inspectors for every retail outlet in 114,000 square miles. Illinois, South Carolina, and Wyoming perform no retail price inspections at all. The regulatory vacuum is not accidental; it reflects a choice to allocate scarce resources toward grocery and big-box stores, leaving convenience stores functionally unpoliced. Both chains deflected with boilerplate. 7-Eleven cited its 3,000+ products per store and "processes in place to correct" discrepancies. Circle K said it is "committed to complying with all applicable laws." Neither answered detailed questions. Legal scholar David Friedman of Willamette University noted the absurdity: companies that have invested in sophisticated inventory management systems claim they cannot keep shelf prices accurate. The systems exist; the incentive to use them for consumer benefit does not. The vendor defense — that suppliers like Coca-Cola or Frito-Lay affix sale tags but fail to update them — shifts blame without changing outcomes. As Utah's weights and measures manager stated plainly: "The store is still responsible, regardless of who put the price up." Meanwhile, consumer complaints about overcharging at convenience stores sit alongside a broader pattern documented by the Guardian, including Dollar General's continued overcharges after paying millions in state penalties. This is extraction through friction. The amounts are small enough that most customers won't fight, the stores are ubiquitous enough that switching costs are real, and the regulatory apparatus is thin enough that enforcement is effectively optional. When 72% of Americans already believe big corporations are overcharging them — per a 2024 Navigator Research poll — systematic shelf-to-register markups at the nation's most-visited retail format are not a pricing error. They are a business practice.