We buy steam from a neighbouring plant. Does the UK CBAM count it?
Yes. HMRC's guidance counts the emissions from heat brought in from another installation as part of your product's embodied emissions, even though you did not burn the fuel. Ask the supplier for its figures from the latest period; without them, use a standard factor for the most used fuel and assume a 90% efficient boiler.
Why bought heat counts and power does not
UK CBAM direct emissions include emissions from producing heat consumed in production, wherever that heat was made. Grid electricity is not counted until at least 2029. So steam from a park boiler is in, while power from the grid is out.
What to ask the steam supplier
- Tonnes or GJ of steam delivered to you each month.
- The fuel used and its quantity, or an emissions factor per tonne or GJ of steam.
- The period the figure covers: HMRC expects the latest available one.
Meter it
Keep a steam flow meter at your boundary with calibration records. If it fails, fill the gap conservatively, for example from average flow plus a supplement.
Worked example: 1,200 tonnes of steam a month
- Assumed supplier factor: 0.22 tCO2 per tonne of steam, from the figures its coal-fired boiler shares with you.
- Monthly steam emissions: 1,200 x 0.22 = 264 tCO2.
- Year: 264 x 12 = 3,168 tCO2.
- Plant output 18,000 tonnes: 3,168 / 18,000 = 0.176 tCO2 per tonne added to direct emissions.
What Senseible does here
Senseible reads steam supply invoices alongside fuel and power bills, so bought heat appears as its own line. 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.
Sources: HMRC, UK CBAM monitoring, reporting and verification technical guidance (October 2026)
Last reviewed 2026-11-02.