Shipping from
The country the parcel physically leaves from, not where the product was made or where your company is registered. This one choice decides whether the parcel crosses the EU customs border.
Choose a country outside the EU and the parcel is an import: it needs a customs declaration, pays customs duty and is charged import VAT. Choose an EU country and none of that applies, because goods already cleared into the EU move between member states without customs. The United Kingdom has been outside the EU customs union and VAT area since 1 January 2021.
Stock imported in bulk before it is sold is cleared once, at the normal tariff rate, and then ships as EU parcels. Orders already sold to individual customers before import remain distance sales, and customs treat them as such even when they travel together in one shipment.
Goods with preferential origin under a trade agreement, such as UK-made goods that meet the origin rules of the EU–UK Trade and Cooperation Agreement, can be declared at the preferential rate instead of the €3 duty, but only on a full customs declaration and only if the VAT is not paid through IOSS. The calculator does not apply preferential rates.