How CBAM certificates will work: buying, holding and surrendering from February 2027

Much of the CBAM commentary this year has focused on prices. Less has been written about the machinery: how certificates are actually bought, how many you must hold, and what happens at surrender. With sales opening in February 2027, this guide sets out the mechanics that every authorised declarant's finance team needs to understand.

What a certificate is

A CBAM certificate represents one tonne of CO2e embedded in imported goods. Your annual liability is the total embedded emissions in your imports, less the deductions the rules allow: the free allocation adjustment, and credit for carbon prices already paid in the country of origin. One certificate is surrendered for each remaining tonne.

Buying

Certificates are bought through the CBAM registry, not on an open market. There is no trading between companies. For 2026 imports the price is the quarterly figure already being published, which has sat close to €75 per tonne across the first half of the year. From 2027 the price moves to a weekly average of EU ETS auctions, so it will follow the carbon market far more closely and deserves proper treasury attention.

The holding rule

You cannot simply wait until the surrender deadline and buy everything at once. At the end of each quarter, the certificates in your registry account must cover at least half of the liability accrued since the start of the year. In practice this means buying steadily through the year, broadly in step with your imports, which turns CBAM into a rolling cash-flow item rather than an annual bill.

Surrender

Surrender happens once a year. By 30 September you surrender certificates covering the previous calendar year's imports, so the first deadline, 30 September 2027, settles everything imported during 2026. The declaration behind that surrender must be supported by verified emissions data or defaults, which is why the quality of your monitoring and reporting feeds directly into what you pay.

Buy-back and cancellation

Over-buying is only partly recoverable. The registry will buy back surplus certificates at the price you paid, but only up to the number you were obliged to buy during the year under the holding rule, so hoarding or speculation does not pay. Certificates beyond the buy-back limit are eventually cancelled without compensation. The planning consequence is simple: forecast your liability honestly, buy to the holding rule, and avoid building a large surplus.

Getting the estimate right

Everything above depends on one number, your accrued embedded emissions, and that number is only as good as the data behind it. Underestimate and you breach the holding rule. Overestimate and you strand cash in certificates you may not fully recover. The importers who will find 2027 easy are the ones treating emissions data as a live management number through 2026, updated quarterly, checked against supplier declarations, and verified before it reaches the registry.

That groundwork is where CBAM-Assured comes in. We train teams on the certificate mechanics and help importers and suppliers build verifiable emissions data. Contact us before February makes it urgent.

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