Tariff stacking, explained: why your effective rate isn't the one in the headline
Base duty, Section 301, and whatever surcharge is live all stack on the same entry. A plain-English view of how the layers combine into the number that actually hits your landed cost.
- What: Multiple tariff layers combine on a single customs entry
- Impact: Your effective rate is the sum of the stack — rarely the single headline number
When a new tariff action makes headlines, the number in the headline is almost never the number on your entry summary. Duties stack: the base HTS rate sits at the bottom, then Section 301 actions, then whatever additional measure is live at the moment — in early 2026, that’s the Section 122 surcharge that replaced the struck-down IEEPA tariffs. Each layer applies on top of the others, against the customs value.
That’s why two sellers importing what looks like “the same” product can quote wildly different landed costs — their HTS classifications, and therefore their stacks, aren’t identical.
Before you re-price or re-route, compute the full stack for your specific codes against the current schedule. Half the panic we see in seller group chats comes from adding a scary headline rate to an imagined baseline instead of reading the actual entry math.
Informational only — not legal or customs advice. Verify against the primary source before acting.
