Customs Tariff
The customs tariff (تعرفه گمرکی) is the schedule of duty rates attached to the classification of goods. In Iran the tariff combines a customs duty (حقوق ورودی) with other levies, and questions frequently test the difference between the customs duty and the total payable charges. The tariff is structured around the HS: chapters, headings, subheadings, and national tariff lines (8- or 10-digit codes).
Concepts to master: ad valorem versus specific duties, the base on which each rate applies, preferential versus general rates, and how tariff schedules are amended. Understand that the tariff line determines the rate but the value comes from the valuation rules - these two domains are tested together.
Traps: a common error is applying the duty rate to the invoice price rather than the customs value. Another is assuming the headline customs duty is the only charge; the total includes other statutory levies computed on their own bases. Questions may also test which tariff version applies to goods declared on a given date.
Rule of thumb: always separate the rate (tariff) from the base (valuation) and from other charges (domain 6). Compute in that order: classify, value, then apply the rate to the value, then add other levies.
Worked example: goods classified under a line with a 10% customs duty and a customs value of 1,000,000 rials yield 100,000 rials of customs duty. If another levy applies on the same value at 4%, add 40,000 rials; do not apply the 4% to the duty-inclusive amount unless the rule says so.