UK Cbam Rules and Rates
The UK Cbam Rules and Rates carries 5 published figures read from 3 sources' own pages, from 8.78 to 50,000 GBP, read 28 October 2026.
4 of the 17 named sources read in full publish a figure; 13 publish none, read 28 October 2026.
By rule
| Breakdown | Median | Range | Sources |
|---|---|---|---|
| ruleaverage UK ETS price, Q3 2026 (per tCO2e) | 58.15GBP | 58.15 to 58.15GBP | 1 |
| rulefree allowance phase-out reduction factor, 2027 | 97.5% | 97.5 to 97.5% | 1 |
| ruleillustrative 2027 CBAM rate, cement (per tCO2e) | 8.78GBP | 8.78 to 8.78GBP | 1 |
| ruleillustrative 2027 CBAM rate, iron and steel (per tCO2e) | 9.69GBP | 9.69 to 9.69GBP | 1 |
| rulebaseline free allocation percentage, cement | 87.1% | 87.1 to 87.1% | 1 |
| ruleregistration threshold (value of CBAM goods) | 50,000GBP | 50,000 to 50,000GBP | 1 |
| rulereturn and payment deadline, first accounting period | 5month | 5 to 5month | 1 |
| ruletime to amend a return | 3year | 3 to 3year | 1 |
| rulerecord keeping after the accounting period | 6year | 6 to 6year | 1 |
| ruletime to register after becoming liable | 30day | 30 to 30day | 1 |
| rulefree allocation phase-out period | 9year | 9 to 9year | 1 |
| ruleUK ETS auction reserve price, 2027 | 29.01GBP | 29.01 to 29.01GBP | 1 |
Every figure, with its source
One row per published figure: the figure as the source's own page publishes it, the page, and the day it was read. A figure that is not on a page we read is not on this one.
| Source | Figure | Breakdown | Read |
|---|---|---|---|
| HMRC: CBAM policy summary | 50,000GBP | registration threshold (value of CBAM goods) | 2026-10-28 |
| HMRC: illustrative CBAM rates and worked example | 97.5% | free allowance phase-out reduction factor, 2027 | 2026-10-28 |
| HMRC: illustrative CBAM rates and worked example | 87.1% | baseline free allocation percentage, cement | 2026-10-28 |
| HMRC: illustrative CBAM rates and worked example | 58.15GBP | average UK ETS price, Q3 2026 (per tCO2e) | 2026-10-28 |
| HMRC: CBAM factsheet | 30day | time to register after becoming liable | 2026-10-28 |
| DESNZ: UK ETS markets (auctions, reserve price) | 29.01GBP | UK ETS auction reserve price, 2027 | 2026-10-28 |
| HMRC: illustrative CBAM rates and worked example | 9.69GBP | illustrative 2027 CBAM rate, iron and steel (per tCO2e) | 2026-10-28 |
| HMRC: CBAM factsheet | 9year | free allocation phase-out period | 2026-10-28 |
| HMRC: illustrative CBAM rates and worked example | 8.78GBP | illustrative 2027 CBAM rate, cement (per tCO2e) | 2026-10-28 |
| HMRC: CBAM policy summary | 6year | record keeping after the accounting period | 2026-10-28 |
| HMRC: CBAM policy summary | 5month | return and payment deadline, first accounting period | 2026-10-28 |
| HMRC: CBAM policy summary | 3year | time to amend a return | 2026-10-28 |
The sentence each figure was read from (12)
- HMRC: CBAM policy summary, read 2026-10-28:
The value is set at £50,000.
- HMRC: illustrative CBAM rates and worked example, read 2026-10-28:
Free allowance phase-out reduction factor 97.5%
- HMRC: illustrative CBAM rates and worked example, read 2026-10-28:
Table 3: Cement sector — Baseline free allocation percentage Sector Baseline free allocation percentage Cement 87.1% Step 4: Apply free allowance phase-out reduction factor The free allowance phase-out reduction factor reflects the gradual withdrawal of free UK ETS allowances as sectors move from partial protection to paying the full carbon price.
- HMRC: illustrative CBAM rates and worked example, read 2026-10-28:
Year Average UK ETS Price Q3 (July to September) 2026 £58.15
- HMRC: CBAM factsheet, read 2026-10-28:
Ordinarily, the liable person will have 30 days to register with HMRC from the day they become liable.
- DESNZ: UK ETS markets (auctions, reserve price), read 2026-10-28:
This will increase to £29.01 in 2027 due to a yearly, inflation-based adjustment to maintain the ARP’s real value in a standalone scheme.
- HMRC: illustrative CBAM rates and worked example, read 2026-10-28:
Table 1: Illustrative rates (/tCO2e) Iron and steel Aluminium Cement Fertiliser Hydrogen £9.69 £9.79 £8.78 £1.45 £9.24 Worked example — Cement sector The following example shows how the CBAM rate for the cement sector will be calculated.
- HMRC: CBAM factsheet, read 2026-10-28:
The Authority has decided to gradually phase out free allocation over an indicative time frame of 9 years, beginning in 2027, for sectors covered by CBAM.
- HMRC: illustrative CBAM rates and worked example, read 2026-10-28:
Year Calculation Illustrative CBAM rate 2027 £58.15 × [1 - (87.1% × 97.5%)] £8.78/tCO2e
- HMRC: CBAM policy summary, read 2026-10-28:
The following records will need to be held by liable persons for 6 years after the end of the accounting period the goods are attributed to.
- HMRC: CBAM policy summary, read 2026-10-28:
After the initial annual accounting period with a 5 month return and payment deadline the subsequent accounting periods will be as follows:
- HMRC: CBAM policy summary, read 2026-10-28:
Amendments must be made within 3 years of the end of the accounting period to which the return relates.
Read in full, publishes no figure
13 named sources were read in full on the dates shown and print no usable figure. They are counted, never filled in.
- gov.uk: prepare for CBAM (collection), read 2026-10-28: read in full and no accepted figure on the page
- HMRC: check if you'll need to register for CBAM, read 2026-10-28: every candidate on the page was refused
- HMRC: work out the date you'll need to register, read 2026-10-28: every candidate on the page was refused
- HMRC: goods that may not count towards the threshold, read 2026-10-28: every candidate on the page was refused
- HM Treasury: introduction of CBAM, read 2026-10-28: every candidate on the page was refused
- HMRC: CBAM policy update, read 2026-10-28: read in full and no accepted figure on the page
- HMRC: draft emissions and verification regulations, read 2026-10-28: read in full and no accepted figure on the page
- Finance Act 2026 Part 5 (CBAM), read 2026-10-28: every candidate on the page was refused
- SI 2026/809: calculation of CBAM rate and carbon price relief, read 2026-10-28: every candidate on the page was refused
- SI 2026/802: CBAM administrative provisions, read 2026-10-28: read in full and no accepted figure on the page
- SI 2026/830: CBAM transitory provision, read 2026-10-28: every candidate on the page was refused
- SI 2026/995: CBAM emissions and verification, read 2026-10-28: every candidate on the page was refused
- Greenhouse Gas Emissions Trading Scheme (Amendment) Order 2026, art 26, read 2026-10-28: read in full and no accepted figure on the page
Methodology
Every row is a verbatim sentence read from the named source's own page through our fetch service on the date shown, hash-pinned to the stored read (the sha of the page's visible text; the raw page is mirrored to R2).
4 of the 17 named sources that could be read published a usable figure; 13 published none and are recorded as not published, never filled in; 0 could not be read (blocked, dead or unreachable) and count nowhere.
The headline figures (median, minimum, maximum, quartiles) are over ONE figure per source for each breakdown it prices, in GBP (a source's median where its page yielded several accepted sentences for one breakdown), so a page that gives figures for several breakdowns gives one for each and N counts 5 figures, never sentences; 73 candidate sentence(s) were refused by a reviewer with the reason recorded.
The fuller derivation this dataset is chartered to grow into (not yet what the figures above are; they are each source's own published figure as read): per sector and quarter the CBAM rate computed exactly as SI 2026/809 sets it (the preceding quarter's average UK ETS auction clearing price x (1 - the sector's free allocation share x the phase-out factor)), the registration test arithmetic (£50,000 forward 30 days and backward 12 months, excluded goods), carbon price relief, and the charge for a given tonnage and CN code (rate x weight x actual or default tCO2e per tonne, less relief); the official rate replaces HMRC's illustrative rate the quarter it is published
73 candidate sentences on these pages were refused by a reviewer; each refusal and its reason is recorded in the review ledger.
Sources (17)
- HMRC: illustrative CBAM rates and worked example(the publisher's own terms; quoted for reporting and comment)
- HMRC: CBAM policy summary(the publisher's own terms; quoted for reporting and comment)
- gov.uk: prepare for CBAM (collection)(the publisher's own terms; quoted for reporting and comment)
- HMRC: check if you'll need to register for CBAM(the publisher's own terms; quoted for reporting and comment)
- HMRC: work out the date you'll need to register(the publisher's own terms; quoted for reporting and comment)
- HMRC: goods that may not count towards the threshold(the publisher's own terms; quoted for reporting and comment)
- HMRC: CBAM factsheet(the publisher's own terms; quoted for reporting and comment)
- HM Treasury: introduction of CBAM(the publisher's own terms; quoted for reporting and comment)
- HMRC: CBAM policy update(the publisher's own terms; quoted for reporting and comment)
- HMRC: draft emissions and verification regulations(the publisher's own terms; quoted for reporting and comment)
- Finance Act 2026 Part 5 (CBAM)(the publisher's own terms; quoted for reporting and comment)
- SI 2026/809: calculation of CBAM rate and carbon price relief(the publisher's own terms; quoted for reporting and comment)
- SI 2026/802: CBAM administrative provisions(the publisher's own terms; quoted for reporting and comment)
- SI 2026/830: CBAM transitory provision(the publisher's own terms; quoted for reporting and comment)
- SI 2026/995: CBAM emissions and verification(the publisher's own terms; quoted for reporting and comment)
- DESNZ: UK ETS markets (auctions, reserve price)(the publisher's own terms; quoted for reporting and comment)
- Greenhouse Gas Emissions Trading Scheme (Amendment) Order 2026, art 26(the publisher's own terms; quoted for reporting and comment)
Cite or embed this figure
The UK Cbam Rules and Rates carries 5 published figures read from 3 sources' own pages, from 8.78 to 50,000 GBP, read 28 October 2026.
4 of the 17 named sources read in full publish a figure; 13 publish none, read 28 October 2026.
UK Cbam Rules and Rates, rule average UK ETS price, Q3 2026 (per tCO2e): median 58.15 GBP across 1 source, read 28 October 2026.
UK Cbam Rules and Rates, rule free allowance phase-out reduction factor, 2027: median 97.50 percent across 1 source, read 28 October 2026.
UK Cbam Rules and Rates, rule illustrative 2027 CBAM rate, cement (per tCO2e): median 8.78 GBP across 1 source, read 28 October 2026.
UK Cbam Rules and Rates, rule illustrative 2027 CBAM rate, iron and steel (per tCO2e): median 9.69 GBP across 1 source, read 28 October 2026.
UK Cbam Rules and Rates, rule baseline free allocation percentage, cement: median 87.10 percent across 1 source, read 28 October 2026.
UK Cbam Rules and Rates, rule registration threshold (value of CBAM goods): median 50,000 GBP across 1 source, read 28 October 2026.
UK Cbam Rules and Rates, rule return and payment deadline, first accounting period: median 5 month across 1 source, read 28 October 2026.
UK Cbam Rules and Rates, rule time to amend a return: median 3 year across 1 source, read 28 October 2026.
UK Cbam Rules and Rates, rule record keeping after the accounting period: median 6 year across 1 source, read 28 October 2026.
UK Cbam Rules and Rates, rule time to register after becoming liable: median 30 day across 1 source, read 28 October 2026.
UK Cbam Rules and Rates, rule free allocation phase-out period: median 9 year across 1 source, read 28 October 2026.
UK Cbam Rules and Rates, rule UK ETS auction reserve price, 2027: median 29.01 GBP across 1 source, read 28 October 2026.
Cite as: "ukcbamcalculator.co.uk UK Cbam Rules and Rates", updated 2026-10-28, https://ukcbamcalculator.co.uk/datasets/uk-cbam-rules-and-rates/.
Download the CSV (12 rows, computed 2026-10-28)