UK CBAM regulations made: what's now fixed, what's still moving

On 13 and 14 July 2026, the government quietly made three of the statutory instruments that put the UK's carbon border tax into operation. No press release led with it; the instruments simply appeared on legislation.gov.uk. But if you import iron & steel, aluminium, cement, fertiliser or hydrogen, this is the moment the deadlines stopped being drafts. Here is exactly what was made, what changed from the consultation drafts, and what is still moving.

The three instruments

• The CBAM (Administrative Provisions) Regulations 2026 (S.I. 2026/802) — made 13 July. Registration: what you must tell HMRC. Returns: what goes in them. Record-keeping.
• The CBAM (Calculation of CBAM Rate and Determination of Carbon Price Relief) Regulations 2026 (S.I. 2026/809) — made 13 July. How the quarterly rate you'll pay is calculated from UK ETS auction prices, and how credit for carbon prices already paid overseas works.
• The CBAM (Transitory Provision) Regulations 2026 (S.I. 2026/830) — made 14 July. The first-year deadline structure.

All three come into force on 1 January 2027, alongside the charge itself.

What is now fixed law

The deadline structure that matters for planning is no longer subject to change-in-consultation:

• Register by 31 January 2028 if you cross the £50,000 threshold at any point during 2027 (the first-year easement, S.I. 2026/830 reg 2(2)). Check whether the threshold catches you.
• The whole of 2027 is one accounting period, with the first return and payment due by 31 May 2028.
• 2028 steps down to quarters: Q1 2028 is due by 31 July 2028, Q2 2028 by 29 September 2028, then the standing rhythm — the last working day of the second month after each quarter.
• Registration particulars (reg 7): business details, EORI number, VAT number, the date you triggered, the value of covered goods imported or expected — and your estimated weight of covered goods per sector for the next 12 months.
• Returns run on 8-digit commodity codes (reg 10) — the level your customs entries already use.
• Records for six years, and — new — records evidencing each good's place of origin (reg 11).
• The rate mechanics (S.I. 2026/809): a quarterly sectoral rate derived from the previous quarter's average UK ETS auction price, reduced for free allocation, with relief for verified overseas carbon prices capped at your CBAM liability.

What changed from the drafts — and what didn't

The reassuring news first: the substance is what was consulted on. The deadlines, the rate formula, the relief cap, the registration particulars — all exactly as drafted in February 2026. If you planned against the drafts, nothing you planned has moved.

Three things did change:

1. The regulations were renumbered. If your adviser's notes cite "draft reg 6" for return contents, that is now reg 10; registration particulars moved from reg 2 to reg 7.
2. The return-contents list got shorter — with a catch. The made rules require, per good: the 8-digit code, weight, carbon price relief amount and place of origin, plus a declaration of accuracy. The draft's explicit emissions detail is gone from the list. Instead, reg 10(3) lets HMRC specify additional return content by notice — which is almost certainly where per-good emissions reporting lands.
3. A new record-keeping duty (reg 11): you must keep records evidencing the place of origin of every good you report — worth checking your broker's paperwork covers this cleanly.

What is still moving

Being straight about the open items:

• The emissions and verification regulations are still draft (consulted April–May 2026, outcome pending) — these govern how suppliers' actual emissions data is measured and verified.
• Default values remain unpublished — the fallback numbers used when you don't have verified supplier data. Promised before 2027.
• The first rate — an illustrative figure is promised for autumn 2026; live quarterly rates from January 2027.
• HMRC's registration service and guidance — expected ahead of 2027; registration is via Government Gateway.
• Penalty amounts — HMRC's existing regimes will apply; specifics to be confirmed.
• UK–EU ETS linkage — talks continue, but there is no exemption: EU-origin goods are chargeable from 1 January 2027 unless and until a linkage agreement is concluded and implemented.

What this means if you import covered goods

Nothing about the sensible plan changes — but the excuse for delaying it just disappeared. The deadlines are now law, and the one deadline that can't be fixed retrospectively is data collection: your May 2028 return is built from evidence gathered during 2027, and a return filed on default values can never later be amended to cheaper, verified supplier data.

So, concretely: check the threshold, work out which of your goods are covered, and start collecting supplier emissions data — our free supplier template is built on the same rules, version-stamped, and updated as the remaining pieces land.

Sources

• S.I. 2026/802 — CBAM (Administrative Provisions) Regulations 2026 (made 13 July 2026)
• S.I. 2026/809 — CBAM (Calculation of CBAM Rate and Determination of Carbon Price Relief) Regulations 2026 (made 13 July 2026)
• S.I. 2026/830 — CBAM (Transitory Provision) Regulations 2026 (made 14 July 2026)
• Finance Act 2026, Part 5 and Schedules 16–19 — the primary legislation
• Draft CBAM emissions & verification regulations (April 2026 consultation) — still draft