Methodology and data sources

How our UK import duty, VAT and landed-cost estimates are calculated from the official UK Trade Tariff, how fresh the data is, what is not calculated, and how to report a correction.

Where the rates come from

Every rate is read from the public UK Trade Tariff API (api/v2/commodities), the official GB tariff service run by HMRC and the Department for Business and Trade. We filter measures by the country of origin you choose. Each result links to the exact tariff page used.

How the estimate is calculated

• Customs value = goods price + shipping + insurance to the UK border (in pounds).
• Duty = customs value × the applied duty rate. The applied rate is the lower of the third-country rate and any preferential rate.
• Import VAT = (customs value + duty) × the standard VAT rate shown for the code.
• Cash outlay = customs value + duty + import VAT. Courier, broker and UK delivery fees are not included unless you enter them.
• Goods of £135 or less (excluding excise goods): no customs duty; VAT is normally charged by the seller instead.

All arithmetic is plain, deterministic code. No AI is used to work out any amount.

What we do not calculate

• Specific, compound or conditional duties (for example per kilogram) — shown as “Not calculated”.
• Excise, anti-dumping, countervailing and additional duties — flagged as warnings, never added.
• Northern Ireland rules, quotas, and reduced or zero VAT rates that need conditions.
• Currency conversion: you enter the HMRC exchange rate or a pound value yourself.

Freshness

Rates are fetched live and kept for up to 6 hours. If the tariff service is down, we may show the last successful result (no older than 48 hours) with a dated warning; otherwise no estimate is shown. Every result carries the time the tariff data was fetched.

Commodity codes

The importer or declarant is legally responsible for the code used. Our AI code finder (run on Cloudflare Workers AI) only shows a code that exists in the live tariff; when it is unavailable it says so. For certainty, HMRC offers Advance Tariff Rulings.

Privacy

Supplier quotes and invoices are read inside your browser and never uploaded or stored.

Corrections policy

If you find a wrong figure, outdated guidance or a broken source link, email limegarth29@gmail.com with the page, commodity code and origin. We check it against the UK Trade Tariff and GOV.UK, fix confirmed errors, and update the “last verified” date on the page.

Official sources

• UK Trade Tariff
• GOV.UK: How to value your imports
• GOV.UK: VAT on imports
• GOV.UK: Tax and customs for goods sent from abroad

Last reviewed 19 October 2026. General guidance only — not legal or tax advice.