CBAM Definitive Period 2026: Declaration Deadlines and Certificate Purchase Dates

The definitive period began on 1 January 2026, but no money changes hands in 2026. Member States start selling CBAM certificates on 1 February 2027. The first annual CBAM declaration, together with the surrender of certificates for goods imported in 2026, is due by 30 September 2027. Certificates covering 2026 are priced at the quarterly average EU ETS auction price for the quarter in which the goods were imported. From 2027, the price is set weekly.

Where these dates come from

The original Regulation (EU) 2023/956 planned for certificate sales and annual declarations to start in 2026. The Omnibus amendment, Regulation (EU) 2025/2083 of 8 October 2025, moved both by a year. Its recital 15 explains that a 30 September deadline gives declarants "more time to collect the necessary information, ensure that embedded emissions are verified by an accredited verifier, and purchase the corresponding number of CBAM certificates". Recital 27 adds that certificates should be sold "in 2027 for emissions embedded in goods imported during the year 2026". The calendar below draws on the consolidated regulation and Implementing Regulations 2025/2548 (certificate price) and 2025/2549 (authorization), all indexed in the EU CBAM knowledge base.

The CBAM compliance calendar, 2026 to 2027

How the 2026 certificate price is calculated

Article 21(1a) of the regulation sets a special rule for emissions declared for 2026. The price is "the quarterly average of the closing prices of EU ETS allowances on the auction platform... of the quarter of importation of the goods". Implementing Regulation 2025/2548 adds the details:

• the input is the auction clearing price of all EU ETS allowances auctioned on the common auction platform and on opt-out platforms. Cancelled auctions are excluded, and so are auctions for buildings, road transport and additional sectors (recital 2);
• each auction price is weighted by the volume auctioned;
• the result is in euros, rounded to the nearest cent;
• the quarterly price applies to certificates corresponding to emissions declared for 2026, for the quarter of importation of the goods (Art. 1(6)).

So a US exporter's shipment cleared in April 2026 and one cleared in October 2026 lead to certificates at two different prices, even though the importer buys both in 2027. The knowledge base does not contain actual ETS auction results, so no euro figure is given here. Check the Commission's published quarterly prices.

From 2027: a weekly price

From 1 January 2027, the Commission calculates the price every calendar week, using the same volume-weighted clearing-price method (IR 2025/2548, Art. 5). It publishes the price on the first working day of the following week, and the price then applies to certificates sold until the next price applies (Art. 21(2)). If a week has no auctions, the price of the last week with auctions is used (Art. 21(1)).

Annual declaration: what goes in it

Under Article 6(2), the declaration filed by 30 September each year contains:

1. the total quantity of each type of goods imported in the previous year, in tonnes or, for electricity, in MWh, including goods below the 50-tonne threshold;
2. total embedded emissions, verified where based on actual emissions;
3. the number of certificates to surrender, after the reduction for any carbon price paid abroad (Art. 9) and the free-allocation adjustment (Art. 31);
4. copies of verification reports, where applicable.

Which year do your goods belong to?

For US producers, the reporting year matters as much as the import date. Implementing Regulation 2025/2620 (recital 12) and the Commission's Guidance No. 2 set a presumption: goods, other than electricity, are treated as produced in the year of import. The declarant can rebut this with evidence of the actual production period, but the reporting period can never fall before 2026. Steel rolled in December 2025 and imported in January 2026 is therefore reported for 2026. The default values that apply if no verified data arrives include a mark-up that is phased in gradually and must be revised by 2027 at the latest (IR 2025/2621). The values themselves are not reproduced in the knowledge base.

Repurchase and cancellation: avoid stranded certificates

• Repurchase of excess certificates is at the price you paid. The request must be made by 31 October of the year of surrender (Art. 23).
• Normally, repurchase is limited to the number of certificates you were obliged to buy under the quarterly rule that year. Certificates bought in 2027 for 2026 emissions may only be repurchased in 2027 (Art. 23(2a)).
• On 1 November 2027, any certificates bought for 2026 emissions that are still on your account are cancelled without compensation (Art. 24(2)). In later years, cancellation on 1 November covers certificates bought in the year before the previous calendar year.
• Fees payable by declarants fund the common central platform (Art. 20(5a)). The fee level is set by delegated act and is not in the knowledge base.

Building your 2026-2027 workplan

1. Now: confirm authorization status. For US exporters, confirm who imports your goods into the EU and whether they hold authorised declarant status.
2. Throughout 2026: track net mass, CN code, origin and quarter of import for every shipment, since the quarter decides the price.
3. Early 2027: collect verified emissions reports from suppliers. The Commission's verification guidance suggests declarants will want them by mid-August at the latest.
4. From 1 February 2027: buy certificates on the common central platform.
5. By 30 September 2027: file the declaration and surrender.
6. By 31 October 2027: request repurchase of any excess before the 1 November cancellation.

You can ask the knowledge base date-specific questions, such as "From what date do Member States start selling CBAM certificates, and for which year's emissions?" Answers quote Regulation 2025/2083 or the price act directly.

Dates reflect Regulation (EU) 2023/956 as consolidated on 20 October 2025 and Implementing Regulations 2025/2548 and 2025/2549 of December 2025. They may change if the texts are amended. This is not legal advice.