Notice of proposal to modify the electricity supply licence Standard Licence Conditions (SLCs) by inserting a new condition, SLC 21D

  • Upcoming
  • Open
  • Closed (awaiting decision)
  • Closed (with decision)

The notice below contains our final proposal to modify the SLCs of the electricity supply licence by inserting a new condition, condition 21D.  This proposed addition affects environmental claims1 on tariffs that supply renewable electricity to domestic customers. The new licence condition will mean suppliers will have to meet requirements on additionality, transparency and evidence of supply, if they offer domestic customers a tariff(s) based on the supply of renewable energy.

  • Additionality: Suppliers will have to make sure that a customer’s choice to purchase a green or renewable tariff results in an additional benefit to the environment, above and beyond existing subsidies, obligations and schemes. They must publish an annual report explaining to their customers how they are meeting this obligation. If they are not offering additionality, they will need to make this clear to customers. We don’t propose defining what should be considered as additionality. Instead, to allow for innovation, we are taking a principles-based approach to additionality. We expect suppliers to engage appropriately to find out what their customers expect in terms of additionality.
  • Transparency: Suppliers must be clear to customers about the environmental claims they make about their green and renewable tariffs. This includes publishing an annual report explaining how the tariff delivers additional environmental benefits. Suppliers will need to clearly tell customers at the point of sale if a renewable tariff does not offer additional environmental benefits.
  • Evidence of supply: Suppliers must have evidence that verifies where the electricity supplied in the tariff comes from. This means that they must show they have enough Renewable Energy Guarantees of Origin certificates and have retired any renewable Levy Exemption Certificates to account for the renewable supply in the tariff.


  1. “Environmental claim” means a claim made in the course of marketing, billing, or other customer communication that says, or may lead a customer to believe, that choosing the particular tariff is delivering an environmental benefit based on the supply of renewable electricity.

Respond name

Natasha Smith

Respond telephone