How to turn a year of plant data into numbers your EU buyers can file.

How Tonnemark works

Since 1 January 2026, EU importers of steel, aluminium, cement, fertilisers and hydrogen must buy CBAM certificates for the emissions embedded in those goods. They can only use your plant’s real figures if you give them, and the figures have been verified. Otherwise they must use the EU’s default values, which are high on purpose and carry a mark-up.

Tonnemark is where you, the producer, record your installation’s fuels, materials, electricity and production. It applies the EU calculation method and produces the one number your buyer needs for each product: its specific embedded emissions, in tonnes of CO₂e per tonne of product. You then share those numbers with each buyer through a private link, with Excel and CSV downloads.

Who does what

Words you’ll see

Installation

One production site, for example a steel mill or a cement plant.

Reporting period

The time span your figures cover, normally one calendar year.

Production process

A part of the plant that makes one kind of CBAM good by one route, such as an electric arc furnace or a rolling mill.

Activity level

Tonnes produced by a process in the period.

Fuels and materials

Everything that releases CO₂ on site: natural gas, coal, coke, limestone, electrodes. The regulation calls these source streams.

Precursor

A CBAM good used as an input to another, such as billets rolled into rebar or clinker ground into cement.

Good

What you sell to the EU, identified by its 8-digit CN code.

SEE

Specific embedded emissions: tonnes of CO₂e per tonne of good. Reported as direct (from fuels and materials) and indirect (from electricity).

Default value

The EU’s fallback intensity for a good from your country, used when the buyer has no actual data.

Benchmark

The EU reference intensity that sets how much of the buyer’s obligation is offset by free allocation.

The workflow at a glance

1. Create a workspace and add your installation.
2. Describe the production processes and how many tonnes each produced.
3. Enter fuels and materials, electricity and precursors, each with its evidence.
4. List the goods you export with their CN codes.
5. Check the results and the verification checklist, then have the period verified.
6. Share a statement with each EU buyer.

Create your workspace

Go to Create a workspace and enter your name, company, country of production, work email and a password of at least 10 characters. You become the workspace owner.

After signing up you land on the Overview. Once you have data, it shows every installation with its latest reporting period, its verification status, how many readiness checks are done, recent buyer activity and what your team changed.

Add an installation

Open Installations → Add installation. Only the name and country are required to start, but your verifier and your buyers need the rest, so fill it in when you have it.

When you save, Tonnemark opens a reporting period for the current calendar year and takes you straight to its Processes tab.

Reporting periods

Each installation has one reporting period per year. Everything you enter (processes, fuels, electricity, precursors, goods) belongs to a period, so last year’s verified numbers stay untouched while you work on this year.

Inside a period, the tabs across the top follow the order you’ll fill them in. A number next to a tab counts its entries; an amber dot means something there needs attention.

Open the next year

On the installation page, choose Open a new period. Pick Copy structure from last year to carry over processes, fuels and materials (with their allocations) and goods. Quantities start at zero, so you only update the numbers.

Status, verifier and locking

In Period settings you can change the dates, record your accredited verifier and verification date, and leave notes for the verifier: your monitoring approach, system boundaries and known gaps.

Production processes

Add one process for each aggregated goods category and route your site produces. A typical EAF mini-mill has two: an electric arc furnace making crude steel and a rolling mill making iron or steel products. A cement plant usually has a clinker kiln and a grinding process.

• Aggregated goods category: grouped by sector (cement, iron and steel, aluminium, fertilisers, hydrogen).
• Production route: for example basic oxygen, electric arc furnace or secondary aluminium. Optional where the regulation doesn’t distinguish routes.
• Activity level: tonnes produced in the period, from your production log.
• Measurable heat imported or exported: only if the process buys or sells steam or hot water, entered as the emissions of that heat in tCO₂e. Imports add to the process; exports subtract.

Fuels and materials

Enter everything that releases CO₂ at the site, with the quantity used in the period. Choose the type that matches how the emissions are calculated:

Use the factor library

Fill from factor library pre-fills the type, unit, calorific value, emission factor or carbon content. The built-in fuel values are IPCC 2006 defaults. Wherever you have supplier certificates or lab analyses, add your own values under Factor library; verifiers prefer them.

Attribute each stream to processes

At the bottom of the form, split the stream across processes in percent. If a gas meter serves both the furnace and the reheating furnace, enter the split from your sub-meters. Each stream should add up to 100%: the Attributed column shows a green 100% when it does, and an amber percentage when part of it isn’t assigned yet.

Always cite evidence

The Evidence field is where you note invoice numbers, meter IDs and lab reports. The verifier will ask for exactly this, and the readiness checklist flags any stream without it.

Electricity

Record the electricity each process consumed, in MWh, with the emission factor of that electricity. These are your indirect emissions.

• Grid: use the country factor the European Commission publishes for CBAM.
• Power purchase agreement or on-site generation: use the actual factor of that generator, with the contract or metering as evidence.
• If a process uses no electricity, enter 0 MWh so the verifier can see it was checked.

Precursors

A precursor is a CBAM good consumed by another process: billets into a rolling mill, clinker into cement grinding, ammonia into fertiliser. Its embedded emissions are carried into your product.

Goods and CN codes

List every product you export to the EU with its 8-digit CN code, the code on your buyer’s customs declaration, and the process that makes it. Each good inherits that process’s intensity.

• CN code: 8 digits, spaces optional (e.g. 7214 20 00).
• Default value (optional): the EU default for your country and CN code, before mark-up, from Implementing Regulation (EU) 2025/2621 as corrected by (EU) 2026/1740.
• CBAM benchmark (optional): the benchmark for the good’s production route.

The default value and benchmark don’t change your emissions. They power the comparison on the Results tab that shows each buyer what your data saves them, which is the strongest argument for staying their supplier.

Reading the results

The Results tab recalculates every time you save. At the top: total direct and indirect emissions, anything not yet attributed to a process, and how many readiness checks are done. Messages in amber explain anything that stops a number being calculated.

Specific embedded emissions by process

For each process you see its own direct and indirect emissions, the emissions it inherits from precursors, and the resulting intensity per tonne. The framed figure on the right is the total, the number your buyers need. Download the full breakdown as Excel or CSV from the buttons above the table.

What your buyers pay

For each good, the bar places your chargeable intensity between the EU benchmark and the default value with its mark-up for the coming import year. The last column is what one buyer saves per 1,000 tonnes by using your data instead of the default, at the certificate price set in Settings.

Before your verifier visits

Nine checks mirror what an accredited verifier asks for:

1. Installation address, coordinates and UN/LOCODE are filled in.
2. Every production process has an activity level.
3. Fuels and materials are fully attributed to processes.
4. Every fuel and material cites its evidence.
5. Electricity is recorded for every process.
6. Precursors use actual supplier data.
7. Goods are listed with CN codes.
8. Default values are entered for the buyer comparison.
9. An accredited verifier is appointed.

Share with EU buyers

Add your buyers

Under Buyers, add each EU importer: company, country, EORI number if you have it, and a contact. The list shows which statements each buyer has and when they last opened one.

Create a statement link

In a reporting period, open Share with buyers. Choose the buyer, when the link expires and which goods to include (a buyer only sees the goods you tick), then Create link. Copy the link and send it to your buyer by email.

• Opened: how many times the buyer viewed it and when. Useful before their filing deadline.
• Revoke: switches the link off immediately. Create a new one if you need to.
• You can share before verification. The statement then says the period isn’t verified yet.

What your buyer sees

A read-only statement with your installation details, the specific embedded emissions per CN code, and the verification status. They can download it as Excel or CSV, or print it to PDF. They don’t need an account. Open the sample statement.

Excel, CSV and PDF

The Excel workbook is laid out after the sheets of the EU communication template for installations, so values can be transferred into the official template if a declarant requires it.

The CSV has one row per good with installation, location, period, CN code, intensities and verification status, ready for a buyer’s customs software. To make a PDF, use Print or save PDFon a statement or invoice and choose “Save as PDF”.

Team and roles

Under Team, owners invite colleagues by email and choose their role. Tonnemark emails them an invitation link, which you can also copy from the page. It works once and expires after 14 days.

Every change is recorded in Recent activity on the Overview with who made it.

Billing and invoices

Tonnemark is billed by invoice: a one-off setup fee for onboarding, then a monthly fee per installation. Billing shows your plan, what’s outstanding and every invoice, each of which you can open and save as PDF.

How payment works

1. When an invoice is issued, it’s emailed to your billing address, and a notice at the top of the workspace shows the amount and due date. Invoices are due within 3 days unless agreed otherwise.
2. Pay by bank transfer to the account on the invoice, with the invoice number as the reference. Then press I’ve made the payment next to the invoice, optionally with a note such as the date and bank.
3. We confirm the payment as soon as it reaches our account. You get a receipt by email and the invoice shows as Paid.

If an invoice is overdue

• We email a reminder the day before an invoice is due, and again once it’s overdue.
• From the day after the due date, a reminder with the payment details appears when you open the workspace. You can postpone it for a day.
• Seven days after the due date, the workspace becomes read-only until payment is confirmed. You can still sign in, read everything and download exports, and your buyers’ statement links keep working.
• Reporting your payment pauses the reminder and the read-only lock for 5 days while the transfer arrives.
• Need more time? Email us before the due date and we can extend it.

Calculation reference

Tonnemark follows the EU calculation-based method for installations. All emissions are in tCO₂e; biomass shares are excluded from fuel and material emissions.

Fuels and materials

Processes and goods

Internal precursors are evaluated first, so a change upstream flows through to every downstream process. A loop between processes is reported instead of producing a number.

What the buyer pays

Chargeable SEE is direct only for iron, steel, aluminium and hydrogen, and direct plus indirect for cement and fertilisers. On default values the same formula uses the default plus its mark-up.

Mark-ups: Implementing Regulation (EU) 2025/2621 (fertilisers 1% flat). Free allocation phase-out: ETS Directive, Art. 10a(1a). The certificate price is your assumption, set in Settings. Rules as of October 2026; check for amendments before relying on cost estimates.

Troubleshooting