Duty is charged on goods entering a country for consumption there. If the goods leave again, a refund mechanism exists, and its details determine whether it is usable in practice.
The principle behind the refund
Import duty is intended to apply to goods consumed domestically. Goods that pass through and are exported were never consumed in the domestic market.
Drawback returns most of the duty paid in that situation, so a domestic processor or distributor is not disadvantaged relative to one operating elsewhere.
A portion is typically retained to cover administration, so the refund is substantial rather than complete.
The main categories of claim
Unused merchandise drawback applies where imported goods are exported in essentially the same condition, without having been used domestically.
Manufacturing drawback applies where imported inputs are incorporated into an article that is then exported, refunding duty on the imported content.
Rejected merchandise drawback covers goods that did not conform to specification or were shipped without consent and are returned or destroyed.
Why substitution rules matter
Tracing a specific imported unit through a warehouse or a production line to a specific export is often impossible with commingled stock.
Substitution provisions allow a claim where exported goods are commercially interchangeable with imported ones, rather than physically the same items.
The test for interchangeability has been defined in different ways over time, and the current basis is generally tied to tariff classification, which made claims more workable for bulk goods.
What claiming actually requires
Claims rest on records: import entries showing duty paid, production or inventory records linking to the exported goods, and export documentation proving departure.
Claims must be filed within a statutory period, and the linkage between the import and the export must fall within defined time limits.
Because the recordkeeping is demanding, many companies use specialist providers, and the fee for that service is part of assessing whether a claim is worth pursuing.
Why some eligible duty goes unclaimed
Many businesses do not realize they qualify, particularly where the exporting entity differs from the importing one and the right to claim has to be transferred.
Others find the administrative cost exceeds the refund for low duty rates or small volumes, which is a legitimate commercial conclusion.
Eligibility, timing and procedure vary by jurisdiction and change over time, so the applicable customs authority and a qualified adviser are where any specific case has to be confirmed.