Calculator methodology

Scope decision

The engine first validates every number, country and category count. It then checks whether the goods were outside the EU when sold, whether the transaction is a commercial online purchase, and whether intrinsic value is no more than €150.

It stops for goods above €150, special fiscal territories, non-commercial gifts, excise or restricted goods, preferential-origin claims and other cases that need normal tariff analysis.

Temporary customs-duty formula

For a supported case, flatDuty = declarationItemCount × €3. The interface calls this input “different tariff-classification categories” and immediately explains that physical quantity alone does not increase it.

Import VAT formula

When VAT was not collected, VAT base = intrinsic goods value + shipping + insurance + temporary customs duty. Import VAT = VAT base × the destination standard VAT rate or a manual override.

The carrier administration fee is treated as VAT-inclusive and is kept outside the VAT base because the calculator has no official basis for assuming that every manually entered fee belongs in the import taxable amount.

VAT paid and uncertain states

When destination VAT was correctly collected at checkout, estimated additional import VAT is €0 while the temporary duty remains. When the user is unsure, the engine returns two complete scenarios rather than choosing an answer.

Money and rounding

All monetary inputs and outputs use integer cents. Percentage rates are stored as basis points. VAT is rounded to the nearest cent using integer arithmetic after multiplying the VAT base by the rate.

Displayed totals are sums of already-rounded cent amounts. Raw binary floating-point values are never used for displayed money.

Known limitations

A consumer usually cannot see the final customs declaration line structure. Product-specific reduced VAT rates, carrier procedures, national reliefs, normal tariffs, origin evidence and declaration choices can change a real assessment.

The legal regulation specifically frames the temporary duty around IOSS and postal consignments. Commission implementation guidance describes broader distance-sale operation across VAT procedures. The site records that nuance and avoids claiming universal coverage for every courier flow.