Rules for biomass fuel use

Rules for biomass fuel use

What are the requirements?

All applicants with biomass systems must use an approved sustainable fuel from a supplier listed on the Biomass Suppliers List (BSL). Please see our key terms for more information about biomass sustainability and biomass supplier’s list.

New fuel quality requirements came into force on 1 April 2022 and all fuels on the BSL must now meet this new fuel quality criteria. 

Woodsure, which operates the BSL, will delist any suppliers whose fuel does not meet the requirements. We therefore recommend you check with your fuel supplier that they will retain their BSL registration.


If you use fuel from your own land/woodland, you may be considered a ‘self-supplier’. You must register the fuel you use on the BSL and list yourself as a ‘self-supplier’. You should contact BSL to confirm your woodfuel meets the new fuel requirements. Any woodfuel not deemed to meet the criteria will be removed from the BSL register.

If you self-supply but also buy in raw materials which you process yourself, you must register on the BSL as a ‘producer-trader’. You do not need to register separately as a self-supplier.

For more on how to register and self-supply classifications, view the BSL guidance.

How to prove you’re using an approved fuel

A statement about fuel will be included in your 'annual declaration' which is how we check that you’re still complying with your ongoing obligations. In it you'll have to enter the BSL authorisation number for each fuel you use, which you should be able to find on your fuel receipts. If you're a self-supplier or producer-trader, you'll need to enter the BSL authorisation number you received from the BSL administrator, along with the numbers of any other fuel you use. BSL authorisation numbers take the format 'BSL-1234567-1234'.

Keep a record of your fuel purchases which show your fuel authorisation numbers. You'll need them not only for your annual declaration submission, but also if we select your biomass heating system as part of our ongoing audit checks.

Something you don't understand? Check our key terms.