UK REGO Regulations SI 2003/2562: Solar Guarantees of Origin Guide

Key Takeaways

• S.I. 2003/2562 established the Renewable Energy Guarantees of Origin (REGO) framework.
• Ofgem (the Gas and Electricity Markets Authority) is designated as "the Authority" for REGO administration.
• One guarantee of origin is issued for each kilowatt hour of electricity produced from renewable sources.
• The electronic Register serves as conclusive proof of a guarantee of origin's subsistence and its registered holder.

Understanding the UK REGO Framework

The Renewable Energy Guarantees of Origin (REGO) framework in Great Britain is established by Statutory Instrument S.I. 2003/2562, formally known as The Electricity (Guarantees of Origin of Electricity Produced from Renewable Energy Sources) Regulations 2003. This statutory instrument defines the rules for authenticating electricity produced from renewable energy sources.

The regulations appoint the Gas and Electricity Markets Authority as "the Authority" responsible for issuing guarantees of origin. We checked on 23 August 2026 that Regulation 3 provides for guarantees of origin to be issued by this body. The Authority is commonly known as Ofgem.

Issuance and Proof of Ownership

Under S.I. 2003/2562, one guarantee of origin is issued for each kilowatt hour of electricity produced from renewable energy sources. This issuance is subject to rounding upwards or downwards. The regulations specify that where a guarantee of origin has been issued and not revoked, no further guarantee of origin can be issued for the same electricity.

A unique number, referred to as the "guarantee sequence number," is allocated to each guarantee of origin issued. These particulars are entered into an electronic Register. The Register is conclusive as regards whether a guarantee of origin subsists and as to the person who is for the time being its registered holder. This means the electronic record is the definitive proof of ownership and existence.

Transfer and Revocation of REGOs

The framework includes provisions for the transfer of REGOs. If the registered holder of a guarantee of origin requests the Authority to transfer that guarantee of origin to any other person, the Authority must do so. This facilitates the trading and movement of REGOs within the market.

The Authority also holds powers to revoke guarantees of origin. We verified on 23 August 2026 that revocation can occur if the Authority is satisfied that the guarantee of origin should not have been issued, is inaccurate, or was issued to the wrong person. Revocation can also happen if the information provided for its issuance was incorrect in a material way. When a guarantee of origin is revoked, the Authority must give notice of such revocation in writing to the registered holder.

Monetisation and Market Context

While S.I. 2003/2562 defines the regulatory backbone, the market for REGOs allows solar asset owners to monetise their renewable electricity generation. One REGO is issued per unit of renewable electricity generated. Standard commercial trading often occurs in 1 MWh batches, equivalent to 1,000 kWh.

REGO certificates authenticate green electricity tariffs for domestic and commercial energy suppliers. This is done under Fuel Mix Disclosure (FMD) rules. Solar asset owners can monetise REGOs in two ways: either alongside physical power sales within corporate Power Purchase Agreements (PPAs) or through standalone certificate trading platforms. We have not verified specific trading platforms or PPA structures, so we do not publish them.

The regulations also state that a competent authority shall recognise a guarantee of origin issued by the Authority under regulation 6(1). This ensures the validity of UK-issued REGOs within broader contexts.