Editorial policy

This page describes how Marginely pages are sourced, checked and corrected; what the site collects is covered separately in the privacy note, and the conditions for using the tools are in the terms. It records the procedure that is actually in place for the calculators and checklists on this site.

Who publishes

Pages are written and maintained by Marginely Editorial. There are no individual bylines, and we claim no professional qualification in accounting, tax or logistics. Nothing here is financial, tax or legal advice, and using these pages creates no advisory relationship.

What counts as a source

A rate is taken only from the party that sets it: Amazon's selling-partner fee announcements and its published Seller Central fee tables, Walmart's and TikTok Shop's own seller pricing pages, and the carriers' published rate and service guides. Where a carrier's page draws its amount table with JavaScript, the amounts are taken from that carrier's rate PDF instead, and the PDF is what we cite. Seller newsletters, agency blog posts and forum threads are not used as the source of a figure, however well informed they are.

Sources are linked on the page

A page's sourced figures carry the documents behind them as real links, so a reader can open the schedule and find the rate. A source mentioned in prose but not linked does not count: the audit only registers a source that is an actual link on the page, and it lists every page that carries no linked source until one is added.

The checks that run on their own

Each marketplace and the shipping surcharges have a fee watcher on its own monthly cycle: Amazon on the 5th, Walmart on the 10th, TikTok Shop on the 1st and the 15th, and shipping on the 8th, with a second pass in the general-rate-increase window at the turn of the year. Each watcher fetches the published schedule and reports when the page it watches changes, so a fee revision reaches us from the schedule rather than from a reader.

A separate audit runs every Friday. It takes the figures shown on each page, fetches the sources linked from that page and checks whether each figure appears in the source text. Each figure comes out confirmed, not found, or uncollected for that week. The audit also judges the source: when almost none of a page's figures appear in the document it cites, the finding is that the source does not cover the page, and the page is queued for a better one. A source that fails to load three weeks running is reported as unrecoverable, and source text that was collected is kept as a local copy so one bad week at the publisher is not mistaken for a changed rate.

Every push to the site also runs an HTML integrity scan that rejects truncated or half-written pages before they are published.

What happens when a figure does not match

The published schedule wins, not the page. If the schedule now says something different, the page is edited to match it, including the wording around the figure. If a figure cannot be found in any published schedule, it is removed rather than replaced with a plausible substitute. If the figure is right but the cited document does not carry it, the source is replaced with the document that does, and the replacement is linked on the page.

Numbers that are ours

Some numbers on the site are not a schedule's: worked examples, the values a calculator starts with, and assumptions a page states as its own, such as an illustrative return rate. So are estimates of costs no marketplace sets — prep-centre and 3PL charges, for example. These are outside the source check.

AI in the workflow

Drafts, page structure and explanatory text are produced with the help of AI tools. A figure we add or change is checked against the published schedule that sets it, and the Friday audit then re-checks the published figures against the same documents.

Reporting an error

Send corrections through the contact form. The most useful report names the tool, the figure you think is wrong and the published schedule you are reading; with that we can open the schedule and correct the page. We cannot review an individual seller account, and we do not give advice through the form.

Limits to carry with any figure

Marketplace fees change on the marketplace's schedule, sometimes with weeks of notice and sometimes less. A page reflects the published schedules as they read when it was last checked. A calculator's output is an estimate of what a schedule implies, not a reproduction of your settlement report: negotiated rates, measured dimensions and case-by-case decisions are outside what any published table can tell you.