TRADE POLICY | 2026-09-24

Commerce Can Now Bar a Company From Importing Polysilicon Before December 4 — and Customs Brokers Are Given Four Factors to Check

A temporary final rule under Proclamation 11052 sets weekly import caps for new importers of record, monitors existing ones for volumes above their historic averages, and creates a waiver process at bis.gov/232.

On September 24, 2026 the Bureau of Industry and Security published a temporary final rule, Docket No. 260915-0004, RIN 0694-AK57, implementing the anti-stockpiling authority in Proclamation 11052. The proclamation, issued August 6, 2026 at 91 FR 51975, imposed minimum import prices and tariffs on polysilicon and its derivatives under Section 232, effective December 4, 2026. This rule governs the window before that date: Commerce is monitoring importers for volumes substantially above their hist

On September 24, 2026 the Bureau of Industry and Security published a temporary final rule titled "Measures To Restrict Stockpiling of Polysilicon and Polysilicon Derivatives Under Proclamation 11052," carrying Docket No. 260915-0004 and RIN 0694-AK57. It is effective September 22, 2026 through December 3, 2026 — a rule with an expiry date built into it, because it governs a single window.

That window exists because of what happens the day after it closes.

What Proclamation 11052 did, and why the date matters

On August 6, 2026 the President issued Proclamation 11052, "Adjusting Imports of Polysilicon and Its Derivatives Into the United States," published at 91 FR 51975. Acting under Section 232 of the Trade Expansion Act of 1962, as amended, 19 U.S.C. 1862, the proclamation found that imports of polysilicon and polysilicon derivatives threaten to impair the national security of the United States, and imposed minimum import prices and tariffs on those products.

Those import adjustments take effect December 4, 2026.

The minimum import price mechanism is worth pausing on. Section 232 actions normally take the form of an ad valorem duty or a quota. A minimum import price sets a floor beneath which the merchandise cannot be entered at all, which is a structurally different instrument — it targets the price of the transaction rather than adding a percentage to it. Importers who have modelled Section 232 exposure as "landed cost plus a percentage" will need a different model here.

Any announced future restriction creates an obvious incentive: bring in as much as possible before it starts. Proclamation 11052 anticipated that and authorized the Secretary, in coordination with CBP, to restrict imports by companies that are stockpiling ahead of December 4. This rule is the machinery for doing it.

Existing importers: monitored against their own history

Commerce states that it is monitoring imports of polysilicon products to identify importers of record that are stockpiling. Where it finds an importer bringing in volumes substantially greater than that importer's historic averages, Commerce will give CBP written notice, and CBP will notify both the importer and any customs brokers conducting business on its behalf.

The consequence is not a penalty or a duty. It is a prohibition: those importers will be prohibited from making further entries of polysilicon products into the United States prior to December 4, 2026.

The test is fact-specific, and the rule lists the factors Commerce will weigh — expressly as a non-exhaustive list:

The aggregate volume imported since Proclamation 11052 issued on August 6, 2026; the weekly average volume imported since August 6, 2026; the weekly average volume imported between January 1, 2026 and August 6, 2026; the weekly average volume imported in 2025; and the use of affiliates.

Read those four volume measures together and the design is clear. Commerce is comparing your post-proclamation behaviour against three separate baselines — the recent pre-proclamation period, the prior full year, and your own running average. An importer whose genuine business simply grew will have a consistent story across all three. An importer who stepped up sharply on August 7 will not.

New importers: hard weekly caps, stated in units

Importers of record that registered with CBP on or after August 6, 2026 are treated differently. Absent Commerce approval, they are prohibited from importing polysilicon products before December 4, 2026 in weekly volumes greater than these quantities:

HTSUS 2804.61.00 — 12 kg per week.
HTSUS 3818.00.0020, 3818.00.0040, 3818.00.0045, 3818.00.0050 and 3818.00.0091 — 7 kg per week.
HTSUS 8541.42.00 — 2,000 units per week.
HTSUS 8541.43.00 — 55 units per week.

Commerce states these figures are based on historic import data and are set so that new importers can bring in at or below the volumes typical of existing importers. It reserves the right to adjust them if necessary to address stockpiling.

These are small numbers. Twelve kilograms of silicon under 2804.61.00, or fifty-five units under 8541.43.00, is not a commercial shipment for most operations — which is the point. A newly created importer of record is not a viable route around the December 4 date.

The anti-circumvention provision, aimed at structure rather than goods

The rule states that Commerce and CBP will coordinate to take action against importers and customs brokers that establish, use, or facilitate multiple importers of record, or other arrangements, for the purpose of circumventing these requirements.

That sentence reaches a specific and familiar tactic: spreading volume across several newly created IOR numbers so that no single one exceeds a cap. It is worth reading alongside CBP's separate enforcement of importer of record data accuracy under Executive Order 14411, which began voiding IOR numbers for inaccurate CBP Form 5106 information on September 18, 2026. The two programs point the same direction — the agencies are increasingly interested in who actually stands behind an importer of record.

Four factors customs brokers are told to consider

The rule addresses brokers directly, reminding those who enter polysilicon products or act as importer of record between September 22 and December 4, 2026 of their affirmative obligation to avoid facilitating violations. It then sets out what a broker should at least consider in judging whether a new importer may be using its services to violate the restriction:

Status — whether the importer is a new IOR established on or after August 6, 2026.
Import behaviour — for new IORs, whether they have made other entries of polysilicon products during the current week, and the precise volume already entered.
Ownership — the direct and indirect beneficial owners, whether those owners have created other new IORs to import polysilicon products, and whether those other IORs have met or exceeded the weekly quantities.
Disposition of the merchandise — the ultimate consignee and delivery user, and whether the goods will be transferred to or used for the benefit of an importer already subject to a prohibition.

The rule warns that broker actions to evade the stockpiling prohibition may result in CBP enforcement.

The ownership factor is the demanding one. It asks a broker to know the beneficial owners of a new client and whether those owners have set up other importers — a diligence standard well beyond confirming a power of attorney. Brokers handling solar-sector entries should decide now what they will ask new clients, and record the answers.

The waiver process

Companies prohibited or restricted may apply to Commerce for a waiver. For an existing importer under a prohibition, a waiver allows importing to resume. For a new importer under the quantitative caps, a waiver allows it to import subject instead to the restrictions that apply to existing importers.

Applications are available at bis.gov/232 and are submitted electronically to BIS. A complete application covers three sections:

Organization information — full legal name, address, ownership structure and beneficial ownership, including the country of headquarters, the authorized representative's details, and information about what the company manufactures and where.

Projected type, volume and use of imports — how the company intends to use the material, specifically whether it supports the company's own manufacturing and how, or whether it plans to transfer the merchandise to third parties, plus the anticipated volume before December 4 if a waiver is granted.

Legitimate business purpose — an explanation of the business considerations behind the company's import volumes.

The structure of that application tells you what persuades. A manufacturer consuming polysilicon in its own production, with documented order books and an explicable volume, is making a straightforward case. A company importing to transfer to third parties has a harder one, and the rule asks it to say so expressly.

What California solar importers should do now

First, pull your own import history against the four measures Commerce named — post-August 6 aggregate, post-August 6 weekly average, January to August 6 weekly average, and 2025 weekly average. If your recent weeks diverge from all three baselines, you should expect attention and should be able to explain why.

Second, check whether any entity in your group registered as an importer of record on or after August 6, 2026. If so, the weekly caps apply to it regardless of the group's overall history.

Third, speak to your broker before they raise it with you. They now have a written list of factors to consider, and the ownership question requires information only you can give.

Fourth, if you need volume before December 4, apply rather than improvise. The waiver exists, the application is published, and an approved waiver is a materially better position than an import prohibition contested after the fact.

Fifth, confirm your tariff classification across the listed subheadings. The caps are stated per HTSUS subheading, so which subheading your product falls under determines which limit binds you — a classification question with an immediate operational consequence.

Sixth, treat this as connected to the wider solar trade picture rather than in isolation. Commerce issued final antidumping and countervailing determinations on crystalline silicon photovoltaic cells from India, Indonesia and Laos in September 2026, with rates above 100 percent in the India cases. An importer managing polysilicon timing while also carrying AD/CVD exposure on cells is managing two separate clocks.

Why this rule is worth reading even if you do not import polysilicon

This is the first time in the 2026 Section 232 programs that the government has published an operational anti-stockpiling mechanism with named volume thresholds, a company-level import prohibition, and explicit broker diligence factors. Where one Section 232 action goes, others tend to follow.

An importer facing any announced future restriction should assume that accelerating purchases into the pre-effective window is a visible act, not a quiet one — and that the agencies now have a template for responding to it.

Trembach Law Firm advises importers, manufacturers and brokers on Section 232 exposure, entry planning and CBP enforcement. To discuss polysilicon timing, a waiver application or broker diligence, call (818) 514-7680, reach our Southern California tariff practice, or consult our guide to tariffs, duties and classification.

Frequently Asked Questions

What exactly changes on December 4, 2026 for polysilicon imports?

Proclamation 11052 imposed minimum import prices and tariffs on polysilicon and its derivatives under Section 232, and those import adjustments take effect December 4, 2026. A minimum import price is not an added percentage; it is a floor beneath which the merchandise cannot be entered at all, so an importer modelling this as landed cost plus a percentage will get the wrong answer.

Can Commerce really stop my company importing before that date?

Yes. Where Commerce finds an importer of record bringing in volumes substantially greater than that importer's own historic averages, it gives CBP written notice and the importer is prohibited from making further entries of polysilicon products before December 4, 2026. CBP notifies the importer and any customs broker acting for it.

What are the weekly limits for a newly registered importer of record?

Importers of record that registered with CBP on or after August 6, 2026 are capped, absent Commerce approval, at 12 kg per week under HTSUS 2804.61.00, 7 kg under the listed 3818.00 subheadings, 2,000 units under 8541.42.00 and 55 units under 8541.43.00. Commerce may adjust these figures if needed to address stockpiling.

Which four factors is my customs broker told to check?

The rule directs brokers to consider at least: whether the importer is a new importer of record established on or after August 6, 2026; the importer's other polysilicon entries during the current week and their precise volume; the direct and indirect beneficial owners and whether those owners created other new importers of record; and the ultimate consignee and delivery user, including whether goods will benefit an importer already under a prohibition.

How do I apply for a waiver, and what does Commerce want to see?

Applications are published at bis.gov/232 and are submitted electronically to BIS. A complete application covers organization information including beneficial ownership and where the company manufactures, the projected type, volume and use of the imports including whether they feed the company's own manufacturing or will be transferred to third parties, and an explanation of the legitimate business purpose behind the import volumes.

This article is provided for general informational purposes only and is not legal advice. Reading it does not create an attorney-client relationship. Import restrictions and waiver outcomes depend on the specific merchandise, corporate structure and entry history involved, and no particular outcome is guaranteed. Consult a qualified attorney about your own circumstances.

Contact Trembach Law Firm at (818) 514-7680 for a confidential consultation.

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