# If I buy hydrogen made by electrolysis as an input, what does CBAM need from the supplier?

Canonical: https://senseible.earth/answers/cbam-hydrogen-from-electrolysis-as-precursor

Hydrogen routes with only electricity emissions give a direct figure of zero, but if you use that hydrogen as a precursor you must still name its production route. Using the zero as an actual value needs the producer's installation to be verified under CBAM rules, though a verifier may simplify the work, for example for hydrogen certified as RFNBO.

## Why zero needs proof

For hydrogen as a CBAM good only direct emissions count, and electrolysis has minimal direct emissions. But a buyer who uses that hydrogen as a precursor claims an actual value of zero, and the guidance says that requires verification of the producing installation under CBAM rules.

## What to get from the supplier

- The production route, named.
- The producer's verification report for the production year.
- The sector parameters and identity of the installation, as for any precursor.

## Simpler verification

Using a risk-based approach, verifiers may simplify the work for hydrogen free of direct emissions. The guidance gives an example: hydrogen certified as a renewable fuel of non-biological origin (RFNBO) under the EU Renewable Energy Directive, a certification needed to import green hydrogen under the EU's renewable energy framework.

## Indirect emissions of this hydrogen

If you make ammonia, hydrogen from a separate process such as electrolysis on your site is a precursor listed in Annex II. Its electricity emissions are then left out of the ammonia figure.

## Changed since the transitional period

Until 2025, hydrogen certified under Delegated Regulation (EU) 2023/1184 could use a zero electricity factor. In the definitive period hydrogen's electricity emissions are not counted at all.

## What Senseible does here

Senseible reads electricity bills and purchase invoices into dated records for a plant that buys or makes hydrogen. It does not issue hydrogen certificates or verify a producer's route.

- [Electrolytic hydrogen: direct emissions only](https://senseible.earth/answers/cbam-electrolytic-hydrogen-direct-emissions-only)
- [India green hydrogen and the EU RFNBO threshold](https://senseible.earth/answers/india-green-hydrogen-vs-eu-rfnbo-threshold)
- [When a precursor's electricity emissions count](https://senseible.earth/answers/cbam-precursor-indirect-emissions-annex-ii-rule)

Sources: [European Commission, CBAM Guidance No. 5b, hydrogen (14 August 2026), sections 2.3.3.3 and 3.1.3](https://taxation-customs.ec.europa.eu/document/download/04ceca3b-466e-4ed9-a1a5-a47c2e5e5be0_en?filename=Guidance%20No.%205b%20-%20Sector-specific%20guidance%20document%20on%20hydrogen.pdf), [European Commission, CBAM Guidance No. 3, methods for calculating embedded emissions (14 August 2026), section 4.9.2](https://taxation-customs.ec.europa.eu/document/download/29b9eec7-1a4b-4eb6-ab85-96a0c9e35fd0_en?filename=Guidance%20No.%203%20-%20CBAM%20methods%20for%20the%20calculation%20of%20emissions%20embedded%20in%20goods.pdf)

Last reviewed 2026-10-25.