How ship-compare.com sources rate data, keeps it current, and handles corrections.
The Shipping Rate Estimator and the modeled tiers on the 2026 parcel cost comparison page are built from published carrier rate cards and rate change announcements, mainly the USPS Postal Explorer rate tables, the USPS Newsroom, and the published UPS and FedEx ground and home delivery rate schedules. We do not pull live rates from any carrier's billing API. Every modeled figure is a simplified linear approximation meant for side-by-side comparison, not a substitute for a carrier's own quote.
Rate tiers get reviewed whenever a carrier announces a general rate change, which has historically happened at least once a year, and whenever USPS, UPS, or FedEx changes a structural rule such as a dimensional weight divisor. The current models reflect the USPS divisor change from 166 to 139 that takes effect July 12, 2026. Guides get a lighter pass every few months to fix stale numbers and broken links.
If a modeled figure looks wrong, or a guide cites an outdated carrier rule, use the contact form and name the page and the specific number in question. Corrections get reviewed and, where warranted, published with an updated "last modified" date on the page itself.
Guides and calculator copy are written by Marcus Vance. Chris Terry publishes the site and handles editorial policy and corrections. See the authors page for background on both.