How is the value counted for the UK CBAM £50,000 threshold?
The same value used, or that would be used, to calculate customs duty on import. Two tests apply: on any day, whether imports passing the tax point in the next 30 days will reach £50,000; and on the first of each month, the past 12 months. In 2027, the look-back starts at 1 January 2027.
Which value
- Where duty applies: the customs value for that duty, under Part 12 of the Customs (Import Duty) (EU Exit) Regulations 2018 or the Union Customs Code, as the case may be.
- Where no duty applies: the value worked out as if those rules applied.
- Only goods passing the tax point on or after 1 January 2027 count.
The two tests
- Forward: on any day, if the importer expects CBAM goods worth £50,000 or more to pass the tax point in the next 30 days, liability starts that day.
- Backward: on the first day of each month, if CBAM goods imported in the preceding 12 months reached £50,000, liability starts that day.
What does not count
- Goods processed in a free zone or under inward processing and exported before the tax point.
- Goods under returned goods relief that meet its conditions.
A buyer crossing the line in 2027
- Imports: January £18,000, February £21,000, March £14,000.
- 1 March: look back to 1 January, £39,000. Not met.
- 1 April: £53,000. Met; liable from 1 April 2027.
- Had the buyer on 10 March expected a £55,000 shipment within 30 days, liability would start on 10 March, the earlier date.
What Senseible does here
Senseible's part is on your plant's side: a per-product figure built from your fuel and input invoices. 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, Carbon Border Adjustment Mechanism (CBAM): Policy summary (updated 2 November 2026)
Last reviewed 2026-11-03.