# What are the UK CBAM default values for cement and clinker?

Canonical: https://senseible.earth/answers/uk-cbam-cement-clinker-default

Clinker (2523 10 00) carries 1.433 tCO2e per tonne in HMRC's UK CBAM defaults. Grey Portland cement (2523 29 00) is 1.375, white Portland (2523 21 00) 1.425, aluminous cement (2523 30 00) 2.075, other hydraulic cements (2523 90 00) 1.441, and kaolinic clays other than kaolin (2507 00 80) 0.240.

## Defaults

- 2523 10 00: cement clinker: 1.433 tCO2e per tonne.
- 2523 21 00: white Portland cement: 1.425.
- 2523 29 00: other Portland cement: 1.375.
- 2523 30 00: aluminous cement: 2.075.
- 2523 90 00: other hydraulic cements: 1.441.
- 2507 00 80: kaolinic clays other than kaolin: 0.240.

## A low-clinker cement gains little from a default

The defaults for Portland and other hydraulic cements are all near 1.4 per tonne, so a blended cement with much less clinker is charged almost like OPC on a default. Its advantage only shows in actual verified data, which starts per tonne of clinker and is converted to the cement shipped.

## Only CO2 counts

Cement goods carry carbon dioxide only. Grid power for grinding is outside the charge, which is based on direct emissions; kiln fuel and calcination are where the figure comes from.

## 10,000 tonnes of OPC to a UK terminal

- Default, 2523 29 00: 10,000 x 1.375 = 13,750 tCO2e.
- Simplified actual: 95% clinker x 0.85 tCO2e per tonne of clinker (example figure) = 0.8075 per tonne of cement.
- 10,000 x 0.8075 = 8,075 tCO2e, if verified.

The clinker figure is an example and the conversion simplified; the force of law notice's equations decide the real figure.

## What Senseible does here

Senseible reads coal, petcoke and alternative fuel invoices with clinker and cement output, so your figure can be set against 1.433 or 1.375 before your buyer chooses. We build the figure from your records and check every figure in-house; for the UK it must then be verified by a verifier accredited for UK CBAM. Have your own verifier? Send it to them.

- [UK CBAM for Indian exporters](https://senseible.earth/cbam)
- [UK CBAM unit for cement and fertiliser](https://senseible.earth/answers/uk-cbam-cement-fertiliser-functional-unit)
- [What a CBAM verifier checks at a cement plant](https://senseible.earth/answers/what-cbam-verifier-checks-cement-plant-india)

Sources: [HMRC, UK CBAM cement default values (published 16 October 2026)](https://www.gov.uk/government/publications/check-the-default-values-for-the-carbon-border-adjustment-mechanism-cbam/cement-default-values), [HM Treasury and HMRC, UK CBAM policy summary](https://www.gov.uk/government/publications/carbon-border-adjustment-mechanism-cbam-policy-summary/carbon-border-adjustment-mechanism-cbam-policy-summary)

Last reviewed 2026-11-03.