China fiberglass tariffs 2026: what changes for importers

Key data

European importers of continuous filament fiberglass originating in China face an urgent problem: the tariffs they had been applying since 2025 contained material errors that have just been corrected by the Commission Implementing Regulation (EU) 2026/716, published on 27 March 2026 and effective from 26 March 2026.

This is not a change in tariff policy: it is a technical correction. But its consequences are very concrete: if your customs declarations were based on the incorrect rates in the 2025 regulations, you must act now.

What does this regulation establish?

Regulation 2026/716 corrects material errors detected in two 2025 regulations that modified duties on Chinese fiberglass. The regulatory chain affected is as follows:

Regulation 2021/328 established definitive countervailing duties after detecting subsidies from the Chinese State to its exporters. Regulation 2023/1452 established definitive antidumping duties following a full interim review. Both were revised in 2025 — the first following a partial interim review limited to injury, the second following a full interim review — and those 2025 revisions contained material errors that are now being corrected.

The result: the tariff rates applicable to Chinese continuous filament fiberglass are technically refined with this correction.

Economic and operational impact

A correction of material errors in tariffs is not a minor formality. It has direct economic consequences for any company that has imported this material since the 2025 regulations came into force.

• Altered import costs: If the corrected rates differ from those applied, companies may have overpaid or underpaid in their customs settlements.
• Risk in customs declarations: Declarations submitted with the incorrect rates may require rectification before the Tax Agency or corresponding customs authority.
• Supply contracts at risk: Contracts signed with prices calculated on the previous rates may need review if the actual cost of importation has changed.
• Most exposed sectors: Construction, automotive and composite materials are those that consume the largest volume of Chinese continuous filament fiberglass and, therefore, those that may suffer the greatest economic impact.

Who does it affect?

• Direct importers of continuous filament fiberglass originating in China that have carried out operations under the 2025 regulations.
• European manufacturers that use this material as raw material in their production processes, especially in the construction, automotive and composite materials sectors.
• Customs and compliance managers of companies with import operations from China in this product.
• CFOs and financial directors who must assess the impact on production costs and margins.
• Customs advisors and customs brokers who manage import declarations for their clients in this sector.

Practical example

A manufacturer of automotive components that regularly imports continuous filament fiberglass from China carried out several import operations between the entry into force of the 2025 regulations and the publication of this correction on 27 March 2026.

In each of those operations, it applied the tariff rates — both the countervailing duty of Regulation 2025/2328 and the antidumping duty of Regulation 2025/2337 — which are now declared to be erroneous. If the rates corrected by Regulation 2026/716 are different from those it applied, this manufacturer must:

1. Calculate the difference between the applied rates and the corrected rates for each operation.
2. Determine whether there is a pending tariff debt or a right to reimbursement.
3. Contact its customs agent to assess the filing of amended declarations.
4. Review current supply contracts to adjust prices if the actual cost of importation has varied.

This process is especially critical for companies with high import volumes, where small differences in the tariff rate translate into significant amounts.

What should companies do now?

1. Identify all affected imports: Locate all import operations of continuous filament fiberglass of Chinese origin carried out under Regulations 2025/2328 and 2025/2337, from their entry into force until 26 March 2026.
2. Compare applied rates with corrected rates: Ask your customs agent or specialized advisor to compare the tariff rates you applied with those resulting from the correction of Regulation 2026/716.
3. Review customs declarations: If there is a difference between the applied rates and the corrected rates, consider filing amended declarations with the customs authority. The deadline and procedure will depend on the customs regulations applicable in each Member State.
4. Review current supply contracts: Analyze whether contracts with suppliers or customers include clauses for adjustment due to tariff variation. If the actual costs of importation have changed, it may be necessary to renegotiate terms.
5. Update internal procedures: Ensure that the purchasing, logistics and finance departments work with the corrected rates for all future operations.
6. Consult with a specialized customs advisor: Given the complexity of the regulatory chain affected (four regulations involved), it is advisable to seek professional advice to assess the specific impact on your company.