UK CBAM · REGISTRATION

Registration is a test, not a choice

UK CBAM registration turns on two statutory triggers. Meet either one and you must register with HMRC. The threshold is an aggregate value of goods, not a volume of emissions — one limb tested on the first day of each month, the other on any day.

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THE TWO TRIGGERS

TRIGGER (A) · LOOK BACK£50,000 over the preceding 12 months

Both conditions must hold together. It is the first day of a month, and during the preceding twelve months the person imported CBAM goods into the United Kingdom, in the course of a business, with an aggregate value of £50,000 or more.

FA 2026 Sch 17 para 2(2)(a)

TRIGGER (B) · LOOK FORWARD£50,000 expected within 30 days

A separate limb. The person is expected to import CBAM goods with an aggregate value of £50,000 or more before the end of a period of thirty days. No import need have happened yet.

FA 2026 Sch 17 para 2(2)(b)

Either limb triggers registration. HMRC's policy summary describes them as two tests.FA 2026 Sch 17 para 2(2)

WHO REGISTERS

LIABLE PARTY

The importer — the person in whose name the customs declaration was made, or on whose behalf the declaration was made or the good imported.

FA 2026 s.146(1), (2)

REGISTERS WITH

HMRC. The Commissioners are responsible for the collection and management of CBAM.

FA 2026 Sch 17 paras 1(1), 2(1)

GOODS COUNTED

Aluminium, cement, fertiliser, hydrogen, iron and steel. Electricity is excluded.

FA 2026 s.143(3) · Sch 16

WHAT IS MEASURED

Aggregate value of the goods for the threshold. The charge itself is on tonnes of CO2e embodied in the goods, at the sectoral domestic price.

FA 2026 s.149(1)

WHEN YOU MUST REGISTER

STANDING WINDOW

Thirty days beginning with the day the person first triggered registration.

FA 2026 Sch 17 para 2(4)

FIRST YEAR

For anyone triggering registration during 2027, that window is replaced by a fixed date: 31 January 2028.

SI 2026/830 reg 2(2)

FULL SEQUENCE

Accounting periods, return dates and payment dates run on their own track.

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AFTER REGISTRATION

Registration is the gate. Once through it, a quarterly return falls due for every accounting period, and the return is per import: an eight-digit commodity code, the weight, the place of origin, any carbon price already paid abroad, and a declaration that the return is true. That record has to be assembled from your suppliers before it can be submitted, and HMRC has not published a data schema.

SI 2026/802 reg 10

Carbon Mandate prepares that record. Submission to HMRC is yours, through the CBAM service on your Government Gateway account.

HMRC draft force-of-law notice, 13 July 2026 · draft, effect 1 January 2027

UK CBAM · JANUARY 2027

Registration is the first date. The data is the long one.

The threshold test is arithmetic. Assembling a defensible emissions record per supplier, per import, per quarter is not.

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