Antidumping duties offset imports sold below fair value, and countervailing duties offset foreign government subsidies. Unlike ordinary tariffs, these duties are set company by company, reviewed annually, and can be adjusted retroactively, meaning the rate on goods you imported years ago can change and a bill can follow. That retroactivity is the part importers miss.
Two duties, two different accusations
Antidumping and countervailing cases sound alike and are not. Antidumping targets pricing: a foreign producer selling into your market below the price in its home market, or below cost. Countervailing targets subsidies: a foreign government giving its producers advantages like cheap loans, tax breaks, or subsidised inputs. One accuses the company, the other the state, and both end as extra duties on specific products from specific countries.
For more on this, see this related guide and our earlier explainer on the same theme.
The cases are brought by domestic industries petitioning their government, investigated by agencies, and applied to defined product scopes. Scope is everything. A case may cover a product category with a written description that sweeps in goods nobody casually associates with it, which is why importers discover exposure in a scope ruling rather than in the case headline.
Why the rate you pay at entry is provisional
Here is the structural surprise: antidumping and countervailing duties work on a retrospective system in the United States. At entry you deposit estimated duties at the current cash deposit rate. Later, an annual administrative review recalculates the actual dumping or subsidy for that period, company by company, and the final liability is assessed at the reviewed rate, higher or lower, with interest.
That means an entry is not truly settled for years. A supplier's rate can jump in review, and the importer of record, usually you, not the supplier, owes the difference. Importers who priced products off the deposit rate and never reserved for adjustment discover that their most profitable line was profitable at a provisional number.
Company specific rates and the supplier question
Rates attach to the foreign producer or exporter, so your duty depends on who made or shipped the goods, not just what they are. The same product from two suppliers in the same country can carry wildly different rates, and a supplier using another company's name or a transhipment route to borrow a low rate creates liability that flows to the importer when it unravels.
Readers also found this companion piece from our archive useful.
Due diligence is therefore commercial, not just legal. Know your producer, verify they are who the paperwork says, and treat an impossibly low price from a new source in a case affected category as a warning sign rather than a bargain. Courts and customs agencies have limited sympathy for importers who did not ask why the deal was so good.
Managing the exposure in practice
Keep a register of every product you import that falls under any antidumping or countervailing order, with the producer, the deposit rate, the review calendar, and the potential adjustment range. Reserve financially against upward adjustment on open periods, the way you would for any contingent liability, and reflect the true expected rate in pricing.
When a new petition is filed in your category, that is the moment to model, not when the order lands. Petitions are public, preliminary duties can arrive within months, and the investigation period itself can create exposure. Importers who watch petitions get a season to adjust sourcing; importers who watch invoices get a bill.
Frequently asked questions
What is the difference between antidumping and countervailing duties?
Antidumping duties respond to foreign producers selling below fair value. Countervailing duties respond to foreign government subsidies to producers. Both apply on top of ordinary tariffs to specific products, countries, and companies.
Why can I get a bill years after importing?
Because the system is retrospective. You deposit estimated duties at entry, and an annual review later sets the final rate for that period. If the reviewed rate is higher, the importer of record owes the difference plus interest.
Who owes if my supplier misrepresented the goods?
Usually the importer of record, which is typically your business. That is why verifying your actual producer and treating suspiciously cheap supply in case affected categories as a risk signal matters so much.
How do I know if my products are covered?
Check the written scope of each order against your products with your broker, and keep a register of covered items with producers, deposit rates, and review dates. Headlines understate scope; the written description decides.