CBAM definitive period timeline: every date from 1 January 2026 to full certificate cost in 2034
The EU Carbon Border Adjustment Mechanism moved from reporting to paying on 1 January 2026, but the money does not change hands until 2027 and the full bill does not arrive until 2034. This page lists the dates in order, each with the regulation behind it. It is refreshed whenever the rule moves; the date at the foot says when it was last checked.
The dates in order
| Date | What happens | Rule |
|---|---|---|
| 1 October 2023 | Transitional period begins: quarterly CBAM reports, no certificates | Regulation (EU) 2023/956, Article 32 |
| 31 December 2025 | Transitional period ends | Regulation (EU) 2023/956, Article 32 |
| 1 January 2026 | Definitive period begins. Free allocation for CBAM sectors 97.5%, so 2.5% of embedded emissions are chargeable | Regulation (EU) 2023/956; Directive (EU) 2023/959, Article 10a(1a) |
| 31 January 2026 | Last quarterly CBAM report (October to December 2025) due | Regulation (EU) 2023/956, Article 35 |
| 31 March 2026 | Importers who apply for authorised CBAM declarant status by this date may keep importing while the application is decided | Regulation (EU) 2025/2083, recital 11 |
| Through 2026 | Only authorised declarants may import more than 50 tonnes net of iron and steel, aluminium, fertilisers and cement in the year; electricity and hydrogen are outside the threshold | Regulation (EU) 2025/2083 |
| 1 January 2027 | CBAM factor rises to 5% (free allocation 95%). Certificate price switches from a quarterly to a weekly average of EU ETS auction prices | Directive (EU) 2023/959, Article 10a(1a); Commission price page |
| 1 February 2027 | Sales of CBAM certificates start on the Commission's central platform. Certificates for 2026 imports are priced on the quarterly average of 2026 EU ETS prices | Regulation (EU) 2025/2083 |
| End of each quarter from 2027 | Declarant must hold certificates covering at least 50% of the embedded emissions in goods imported since 1 January (was 80%) | Regulation (EU) 2025/2083 amending Article 22 |
| 30 September 2027 | First annual CBAM declaration (2026 imports) due, and the matching certificates surrendered (was 31 May) | Regulation (EU) 2025/2083 amending Articles 6 and 22 |
| 31 October each year | Deadline to ask the Commission to repurchase surplus certificates | Regulation (EU) 2025/2083 |
| 1 November each year | Certificates bought in the year before the previous calendar year are cancelled | Regulation (EU) 2025/2083 |
| 1 January 2028 | CBAM factor 10% | Directive (EU) 2023/959, Article 10a(1a) |
| 1 January 2029 | CBAM factor 22.5% | same |
| 1 January 2030 | CBAM factor 48.5% | same |
| 1 January 2031 | CBAM factor 61% | same |
| 1 January 2032 | CBAM factor 73.5% | same |
| 1 January 2033 | CBAM factor 86% | same |
| 1 January 2034 | Free allocation ends; certificates on 100% of embedded emissions | same |
Three things the table implies
2026 is a data year, not a payment year. Nothing is bought or surrendered for 2026 imports until 2027, but the quantity, embedded emissions and origin carbon price for every line imported in 2026 have to be recorded now, because the 30 September 2027 declaration covers all of it. The threshold is by mass, once, for the year. 50 tonnes net across the four mass-threshold sectors combined. An importer at 40 tonnes in June is fine; the same importer at 51 tonnes in November needed declarant status before the tonne that crossed the line. The cost curve bends in 2029 and 2030. The chargeable share goes from 10% to 48.5% in two years. A basket that costs a few thousand euros in 2026 costs twenty times that in 2030 at the same certificate price and the same emissions. The CBAM cost guide sets out the arithmetic and the free estimator runs it.Where the workbook fits
The EU CBAM Cost Calculator 2026 to 2034 carries this schedule on its Factors sheet and prices any basket for any year, with a nine-year projection and a price sensitivity grid. What the annual declaration needs is the same set of inputs.
Sources
- Regulation (EU) 2023/956 establishing a carbon border adjustment mechanism: Articles 6, 22, 32 and 35: eur-lex.europa.eu/eli/reg/2023/956/oj.
- Regulation (EU) 2025/2083 amending Regulation (EU) 2023/956 (CBAM simplification), OJ 17 October 2025, in force 20 October 2025. Read as summarised by Mayer Brown (October 2025), EY (tax alert) and Reed Smith (viewpoints), which agree on every date above.
- Directive (EU) 2023/959, Article 10a(1a): free allocation phase-out schedule: eur-lex.europa.eu/eli/dir/2023/959/oj.
- European Commission, CBAM certificate price page (quarterly average in 2026, weekly from 2027): taxation-customs.ec.europa.eu/carbon-border-adjustment-mechanism/price-cbam-certificates_en.
Last checked against the sources on 19 September 2026.
EU CBAM Cost Calculator 2026-2034 (Excel, every rule sourced)Work out what CBAM costs your imports every year to 2034, with every rule sourced.
See the workbook, $29Free toolTry it in your browser first.
Open the free toolSearch terms this page answers: cbam definitive period timeline, cbam 2026 deadlines, cbam declaration deadline 2027, when do cbam certificates start, cbam free allocation phase out dates, cbam key dates.