The annual mass threshold priced as a cliff: certificates on every tonne, a fixed cost of compliance, and the premium at which buying the last tonnes in the EU wins.
For a small importer the CBAM 50 tonne threshold is a cliff, not a slope. An importer of 30 tonnes of steel and 25 of aluminium a year is 5 tonnes over, and owes on all 55. In 2026 the certificates for those 55 tonnes cost 210 euros; an illustrative 15,000 euros of fixed compliance cost is what makes the last 5 tonnes cost 3,042 euros each. Buying them in the EU at a 150 euro premium costs 750.
Worked in full in The CBAM Compliance Handbook by Julian R. Sterling, with every figure reproduced in a free workbook.See the book on Amazon →
The CBAM regulation, Regulation (EU) 2023/956, was amended in 2025 to replace the original exemption of 150 euros per consignment with an annual mass threshold: an importer whose covered goods total no more than 50 tonnes of net mass in a calendar year is outside the obligations for that year. The threshold is cumulative across iron and steel, aluminium, fertilisers and cement; electricity and hydrogen are not covered by it. An importer that exceeds it must hold authorised declarant status before importing above it, and once the year's total passes 50 tonnes the obligations apply to every covered tonne imported that year, not only to the excess.
| Input | Value |
|---|---|
| Steel imported, tonnes | 30.0 |
| Aluminium imported, tonnes | 25.0 |
| Embedded emissions, steel, tCO2 per tonne | 2.0 |
| Embedded emissions, aluminium, tCO2 per tonne | 1.8 |
| Certificate price, euros (illustrative) | 80.00 |
| Fixed annual cost of compliance, euros (illustrative) | 15,000 |
| EU-sourcing premium on the same goods, euros a tonne (illustrative) | 150 |
The fixed cost is an assumption, and every importer should replace it with its own: the authorised declarant application, the annual declaration, the supplier data requests, verification where actual emissions are used, and the hours of the person who owns it. It does not scale with tonnes, which is the whole point.
At an even 4.58 tonnes a month, the importer has 45.8 tonnes after ten months and 50.4 after eleven. The threshold is crossed in November, and from that moment the year is inside CBAM, back to 1 January. The two categories are added together: neither the steel nor the aluminium alone would have crossed.
Embedded emissions: 30.0 × 2.0 + 25.0 × 1.8 = 60.0 + 45.0 = 105.0 tCO2
2026 certificates: 105.0 × 2.5% = 2.625, at 80 euros = 210 euros
Cost of the 5 tonnes over the line: (210 + 15,000) ÷ 5.0 = 3,042 euros a tonne
In Excel: =IF(B1>50, B1*B2*B3*B4 + B5, 0), with tonnes in B1, average emissions per tonne in B2, the factor in B3, the price in B4 and the fixed cost in B5.
The certificates are on the simplification the book uses, embedded emissions times the CBAM factor; for goods above the product benchmark the obligation is higher, but at these volumes the conclusion does not change.
| Year | CBAM factor | Certificates | Certificate cost | With fixed cost | Per tonne over |
|---|---|---|---|---|---|
| 2026 | 2.5% | 2.625 | 210 | 15,210 | 3,042 |
| 2027 | 5.0% | 5.25 | 420 | 15,420 | 3,084 |
| 2028 | 10.0% | 10.5 | 840 | 15,840 | 3,168 |
| 2029 | 22.5% | 23.625 | 1,890 | 16,890 | 3,378 |
| 2030 | 48.5% | 50.925 | 4,074 | 19,074 | 3,815 |
| 2034 | 100.0% | 105.0 | 8,400 | 23,400 | 4,680 |
Even at the full rate in 2034, the certificates are just over a third of the cost of crossing. For an importer of this size CBAM is a fixed cost with a small variable tail, and the decision is about the fixed cost.
Buying the last 5 tonnes from an EU producer at a premium of 150 euros a tonne costs 750 euros. The break-even premium, at which staying under costs as much as crossing, is 3,042 euros a tonne in 2026 and 3,815 in 2030. No plausible premium on steel or aluminium comes close. Delaying a December shipment to January also works for one year, but it moves the tonnes into next year's count; an importer whose run rate is 55 tonnes crosses every year, and the durable fix is the sourcing.
Do not split the importer. Spreading the same imports across several group entities so that each stays under 50 tonnes is exactly the kind of practice the regulation's anti-circumvention provisions are there to catch. The threshold is a fact about a business's imports, not a target to engineer.
| Tonnes imported | Certificate cost | Fixed cost | Total |
|---|---|---|---|
| 45.0 | 0 | 0 | 0 |
| 49.0 | 0 | 0 | 0 |
| 51.0 | 3,778 | 15,000 | 18,778 |
| 55.0 | 4,074 | 15,000 | 19,074 |
| 70.0 | 5,185 | 15,000 | 20,185 |
| 100.0 | 7,407 | 15,000 | 22,407 |
The jump from 49 to 51 tonnes is 18,778 euros. The next 49 tonnes, from 51 to 100, add only 3,629. The volume at which the certificates alone match the fixed cost is 3,929 tonnes in 2026, 203 in 2030 and 98 in 2034: below those volumes, compliance costs more than carbon.
The common mistake is to treat the threshold as an allowance, assuming that an importer at 55 tonnes pays on 5. It pays on 55, and it needs authorised declarant status before the tonne that takes it over the line. The second mistake is to look only at the certificate cost, conclude that 210 euros is immaterial, and let the threshold be crossed by default. The certificates are immaterial; the compliance is not.
The scope screen with the annual mass threshold is one of the thirteen working documents in the free companion files for this book. The cost per tonne of a larger importer, year by year to 2034, is in how much CBAM will cost per tonne of steel.
It exempts an importer whose covered goods total no more than 50 tonnes of net mass in a calendar year, aggregated across iron and steel, aluminium, fertilisers and cement; electricity and hydrogen are outside it. It replaced the earlier 150 euro per consignment exemption. An importer at 45.8 tonnes after ten months and 55.0 at year end is inside CBAM for the whole year.
No. Once the year's imports pass 50 tonnes, the obligations apply to all the covered goods imported that year. In the worked case, 5.0 tonnes over the line bring 55.0 tonnes and 105.0 tonnes of embedded CO2 into scope, and the importer needs authorised declarant status before importing above the threshold.
It depends on the year. At an average 1.909 tCO2 a tonne and 80 euros a certificate, certificates cost as much as an illustrative 15,000 euros of annual compliance only at 3,929 tonnes in 2026, 203 tonnes in 2030 and 98 tonnes in 2034. For small importers the threshold is mostly about the fixed cost.
This article is one calculation from The CBAM Compliance Handbook. The book takes the same case from first principles to the decision, chapter by chapter, and every figure it prints is a live formula in the free companion workbooks.
Get the book on Amazon →Free companion files
Also on Amazon UK · Amazon Germany · Amazon France · Amazon Canada
Reading guide: regulation, compliance and banking → · All 453 articles →
If this book helped, or didn’t, a few lines on Amazon are worth more than they look: they are what the next reader goes on. Write a review. The workbook stays free either way.