The Carbon Cost of
Imported Steel.
UK CBAM from January 2027.

What Is CBAM, and When Does It Start?

The Carbon Border Adjustment Mechanism is a charge on the greenhouse-gas emissions embodied in certain imported goods. Its purpose is to prevent "carbon leakage" — the situation where UK carbon pricing pushes production and emissions overseas to countries with weaker climate policy, and that cheaper, higher-carbon material is then imported back into the UK.

The UK CBAM takes effect on 1 January 2027 and applies to specified goods imported into the UK on or after that date. It covers five sectors judged to be most at risk of carbon leakage: aluminium, cement, fertiliser, hydrogen and iron & steel. For anyone buying engineering bar, it is the iron & steel scope that matters.

CBAM is distinct from the steel safeguard tariff-rate quotas that changed on 1 July 2026. The quotas limit how much steel can enter tariff-free; CBAM puts a price on the carbon that steel carries regardless of quota. From 2027, a direct importer can be exposed to both at once.

Who Actually Pays — and on What?

CBAM liability falls on the importer: the person in whose name the customs declaration is made, or, where no declaration is required, the person on whose behalf the goods are imported. If your business does not import CBAM goods, you are not the liable person.

Registration with HMRC is triggered once the value of CBAM goods brought in reaches £50,000 across a rolling 12-month look-back, or where you expect to exceed that figure in the next 30 days. Below the threshold, a business stays outside the regime.

The charge itself is built from two numbers: the embodied emissions of the goods and the CBAM rate. Embodied emissions can be calculated two ways:

• Actual emissions — verified emissions intensity (tonnes of CO₂e per functional unit) multiplied by the weight of the goods imported. This requires reliable data from the producer.
• Default values — government-published fallback figures, used where actual data is not available. Default values are generally set conservatively, so relying on them can mean a higher charge.

The CBAM rate reflects the effective carbon price in the UK, adjusted for free allowances under the UK Emissions Trading Scheme, and is recalculated quarterly. From the resulting charge, importers can deduct a carbon price relief for any carbon cost already paid overseas under a qualifying scheme, provided it is properly evidenced.

Why This Matters for Engineering Steel Buyers

For a machine shop, fabricator or procurement team, CBAM changes the arithmetic of buying imported bar in three practical ways.

1. Direct importing now carries a carbon cost and a paperwork cost

A buyer who imports bar directly — or who buys from a distributor that imports on their behalf and passes the cost through — picks up the CBAM charge on top of any above-quota tariff. Just as importantly, they pick up the administrative burden of proving embodied emissions. That favours suppliers who can demonstrate low-carbon or UK-origin material.

2. Emissions data joins the list of things a certificate has to prove

Traceability has always mattered in engineering steel: heat numbers, chemical analysis and mechanical properties on an EN 10204 mill certificate tie a bar back to its cast. CBAM adds emissions intensity to the information buyers increasingly need to see. Material that arrives with clear, verified production data is easier to account for than material that forces you back onto conservative default values.

3. Low-carbon supply — and buying from UK stock — become more competitive

Steel of UK origin is out of CBAM scope entirely. Electric-arc-furnace production — which the UK Steel Strategy is investing to expand — carries lower embodied emissions than blast-furnace steel, and therefore a lower CBAM charge where it is imported. The combined effect of the July 2026 tariff changes and the January 2027 CBAM is to erode the price advantage of importing bar directly, compared with buying from UK stock — where the import, and its carbon assessment, have already been handled.

Which Grades and Sources Are Most Exposed?

For engineering bar, CBAM exposure has little to do with the grade designation and almost everything to do with origin — and the practical reality is that the great majority of engineering steel bar sold in the UK is imported. The table below shows the picture for common grades.

The through-line is simple: because most UK engineering bar is imported, CBAM exposure runs across the range rather than sitting with a few grades — and the size of any charge is set by the supplying mill's carbon route and the quality of its emissions data, not by the grade on the certificate. Sectors that specify tightly — oil & gas, defence and hydraulics among them — will feel this most where a specification pins them to a particular mill or source.

What Should You Do Now?

CBAM does not start until January 2027, but the buyers who handle it well will be the ones who understand their exposure before it arrives. Practical steps:

1. Work out whether you are a "liable person". If you import CBAM goods above the £50,000 threshold, you will need to register with HMRC and report. If you buy finished bar from a UK stockholder, you generally will not — but you should confirm how your current suppliers source their material.
2. Ask your suppliers about origin. For each grade you use in volume, find out whether the material is UK-origin or imported, and whether the supplier can provide verified emissions data or expects to rely on default values.
3. Treat emissions data as part of certification. If you already require an EN 10204 3.1 certificate for traceability, start asking whether embodied-emissions data can be supplied alongside it for imported material.
4. Review specifications that force an imported source. Where a specification pins you to a grade or origin that is import-dependent, it is worth checking — well before 2027 — whether an equivalent UK-stocked grade meets the same requirement. Our grade equivalents table is a useful starting point.

Our View

CBAM is a bigger administrative change than a price change for most engineering buyers. The headline carbon charge will matter on high-volume imported material, but the quieter effect is the reporting burden it places on importers — registration, verified emissions data, returns and payment deadlines. That burden is exactly the kind of thing a stockholder is meant to absorb on a customer's behalf.

We have supplied engineering steel from stock for nearly five decades. The practical lesson through every shift in trade policy has been the same: buyers with a trusted, well-stocked UK supplier at the end of the phone spend less time on paperwork and supply risk than those chasing the cheapest imported price. CBAM, arriving on top of the July 2026 quota changes, only sharpens that point.

If you want to understand how CBAM and the current tariff regime affect the specific grades and volumes you buy, call us. It is the kind of conversation our sales team is good at — a practical read on where your supply sits and what, if anything, needs to change.