Importers must hold a DEA Schedule I or II importer registration (depending on the specific substance) and obtain an import permit for each shipment. The DEA evaluates permit applications against US aggregate production quotas and INCB estimates. FDA registration of the foreign manufacturing site and a valid Drug Master File are also required. Delays in permit issuance can disrupt pharmaceutical manufacturing schedules, so importers typically apply well in advance of planned shipment dates. Consult a licensed customs broker and DEA-registered counsel for current procedural requirements.

The International Narcotics Control Board sets annual global estimates for licit opiate raw material production, and each producing country — including Australia and the UK — operates within those limits. When global demand for opioid APIs rises or a major crop is affected by weather, the quota ceiling can constrain supply even from well-established licensed producers. US pharmaceutical manufacturers typically monitor INCB estimate revisions and coordinate with DEA on domestic quota allocations to anticipate potential shortfalls.