The same monthly internet price can run on a different clock: a seven-offer audit of advertised price terms on US provider pages (observed 21 September 2026)

A fixed, dated snapshot of how seven US home-internet providers' public offer pages described one selected offer each on 21 September 2026 (Spectrum, AT&T, Xfinity, EPB, Kinetic, EarthLink, Optimum). For each offer we coded 22 attributes: displayed monthly rate, stated rate window (the 'clock'), later-price disclosure, AutoPay/paperless conditions, equipment, installation, address qualification, taxes and fees, evidence locators, and a SHA-256 fingerprint of the captured HTML where a direct download succeeded. Three of seven pages stated how long the displayed rate lasts (2, 12 and 60 months); four stated no rate period; four tied the displayed rate to AutoPay or payment method; one placed equipment on its own 12-month clock. Scope: public web pages only. No customer bills, address-qualified quotes, orders or personal data. Seven hand-selected offers cannot rank providers or estimate national prices. Files: advertised-terms.csv (7 rows x 22 columns), README-codebook.md, technical-note.pdf. Canonical web version with dated update notes: https://www.internetservice.ai/research/internet-bill-cost-study Conflict of interest: InternetService.ai is an affiliate-supported comparison site; compensation did not affect which terms were recorded. AI tools assisted with retrieval, coding drafts and editing; the author reviewed every row and is responsible for the content.