REGOs and ROCs solve two different problems. A REGO proves where a unit of electricity came from, one certificate per megawatt hour, and matters most for carbon reporting and Fuel Mix Disclosure. A ROC is the mechanism suppliers use to prove they've met their legal obligation under the Renewables Obligation, backed by a buy-out price if they fall short. For the authoritative detail on either, Ofgem runs both registries.
TL;DR:
- REGOs are linked directly to specific generation sites and months, requiring careful vintage and provenance verification to prevent greenwashing.
- ROCs are used by suppliers to meet annual obligation thresholds, with a buy-out price set at £69.34 per ROC for 2026/27, acting as a soft cap.
- Proper certificate procurement involves checking transfer records on the official register, verifying vintage dates, and accurately tracking retirements at the site level.
- Manual reconciliation methods fail at scale; automated tools like EnerlyticsAI match retirements against half-hourly meter data for more reliable scope 1, 2, and 3 emissions reporting.
- UK regulatory shifts include changing the buy-out price calculation to CPI and the loss of EU recognition for GB REGOs, necessitating regular procurement and compliance reviews.
Table of Contents
- What Is a REGO Certificate and How Does It Work?
- How Do ROCs Drive Supplier Compliance in the UK?
- How Should Businesses Procure and Verify Certificates?
- How Do You Register, Claim, and Present These Certificates?
- Making Certificate Reconciliation Actually Reliable
- Regulatory Shifts Procurement Teams Should Watch
- Where EnerlyticsAI Fits Into Certificate Reconciliation
- Where to Find Official Guidance
- Sources
- FAQ
What Is a REGO Certificate and How Does It Work?
A Renewable Energy Guarantee of Origin gets issued at a fixed rate: one REGO per megawatt hour of eligible renewable generation, with Ofgem administering the whole scheme. Every certificate carries a traceable link back to a specific generating station and a specific month of output, which is the entire point. The electricity itself flows through the grid unlabeled. The REGO is what lets a business claim, on paper, that a particular chunk of consumption was renewable.
Generators accredit their stations on the Renewable Electricity Register, then request REGOs against verified output. From there, certificates can be:
- Transferred to a supplier or trading counterparty
- Retired against a specific claim, such as Fuel Mix Disclosure or an RE100 submission
- Held briefly before resale, since REGOs trade as a commodity separate from the power itself
Statistic Callout: Every REGO represents exactly 1 MWh of generation, no more and no less. That precision is what makes the certificate auditable, but it also means sloppy vintage tracking creates real exposure. GB REGOs carry a shelf life, and once a certificate ages past its window it can no longer support a current-year claim.
That expiry rule is where greenwashing risk creeps in. A business that buys REGOs cheaply without checking vintage or provenance can end up retiring certificates that don't actually cover the reporting period it claims to cover. Treat REGOs as attributes that require the same diligence as any other compliance document, not as a rubber stamp.
How Do ROCs Drive Supplier Compliance in the UK?
The Renewables Obligation works on an entirely different logic than REGOs. Ofgem sets an annual obligation, expressed in ROCs per megawatt hour of supply, and licensed electricity suppliers must either present enough ROCs to cover it or pay a buy-out payment for the shortfall. Guidance for suppliers sets obligation periods running from April 1 to March 31, with compliance reports and certificate presentation due after the period closes.
The buy-out price functions as a soft price cap on the whole scheme. If ROCs on the open market trade above the buy-out price, suppliers simply pay the buy-out instead, which keeps a ceiling on what they'll spend to comply.
| Item | Detail |
|---|---|
| Obligation period | April 1 to March 31 |
| Compliance mechanism | Present ROCs or pay buy-out |
| 2026/27 buy-out price | £69.34 per ROC |
| Redistribution | Buy-out fund paid back to compliant suppliers |
A few mechanics matter for anyone forecasting budget exposure:
- Suppliers who pay into the buy-out fund get money back if their peers also underperform, since the fund redistributes pro rata to suppliers who did present ROCs
- Mutualisation kicks in above a set threshold, spreading losses across the market if a supplier defaults on its buy-out obligation
- Ofgem's own redistribution report for 2024–25 shows suppliers met the large majority of their obligation by presenting actual ROCs rather than paying out, which tells you the certificate market is doing real work, not just sitting as a backstop.
How Should Businesses Procure and Verify Certificates?
Buying certificates without a verification process is how businesses end up with claims they can't defend in an audit. Build the check into procurement, not after it.
- Confirm the certificate's vintage matches the reporting period you need it for, since an expired REGO is worthless for that year's Fuel Mix Disclosure.
- Verify the transfer on the Register itself rather than trusting a trading confirmation alone. The Register is the legal record.
- Read the contract wording carefully. Some agreements convey retirement rights; others only convey resale rights, and the difference matters enormously if your sustainability team assumes retirement happened.
- Reflect retired certificates in corporate reporting at the site level, tying each retirement to the specific consumption it's meant to offset rather than a company-wide average.
- Track buy-out price movements if you're a supplier exposed to shortfall risk, since a market price swing above or below £69.34 changes the economics of buying ROCs versus simply paying out.
Pro Tip: Keep a running reconciliation log that matches each retired certificate to a site and a month. When an auditor asks for evidence months later, you want a record that took five minutes to build, not five days to reconstruct.
Double counting is the quiet risk nobody budgets time for. It happens when a certificate gets claimed by two parties, usually because a resale wasn't cleared through the Register before the buyer retired it. Building registry confirmation into your procurement checklist closes that gap before it becomes an audit finding.
How Do You Register, Claim, and Present These Certificates?
Getting a facility recognized starts with accreditation on the Register, which Ofgem uses to record every transfer, cancellation, and retirement tied to a generating station. Once accredited, generators submit metered output and request REGOs against verified generation.
- Generators claim REGOs within a defined window after the month of generation, so late submission risks losing eligibility for that output.
- Suppliers file compliance reports after each obligation period closes, presenting ROCs or arranging buy-out payment.
- Official forms, fee schedules, and submission portals sit on Ofgem's Renewable Electricity Register, not on third-party trading platforms.
Statistic Callout: Obligation periods run on a strict April to March cycle, and suppliers can bank a portion of ROCs from the prior period to cover a shortfall. Missing the presentation deadline converts what could have been a certificate-backed compliance position into a straight buy-out cost.
Making Certificate Reconciliation Actually Reliable
Manual certificate tracking breaks down the moment a business runs more than one or two sites. Half-hourly consumption data changes that math, because it lets you match retired certificates against actual metered use instead of an annual estimate that papers over monthly swings.
A workable operational flow looks like this:
- Export registry data on transfers and retirements at regular intervals
- Ingest that data alongside automated bill validation, which catches billing errors before they distort your consumption baseline
- Generate a site-level retirement log that ties each certificate to a specific meter and month
- Produce a vintage reconciliation report ahead of any Fuel Mix Disclosure or Scope 2 submission
Pro Tip: Auditors respond well to a retirement log that shows the meter, the month, and the certificate ID on one line. Anything less specific invites more questions, not fewer.
None of this replaces the registry itself. Issuing, transferring, and retiring certificates stays entirely within Ofgem's systems. What analytics adds is the reconciliation layer that keeps your internal reporting honest against what's actually on the Register.
Regulatory Shifts Procurement Teams Should Watch
Ofgem is shifting the buy-out price calculation from RPI to CPI, which changes long-term forecasting math. Post-Brexit, GB REGOs no longer carry EU recognition, and GB and Northern Ireland now run under different rules. Build a regulatory review into every annual procurement cycle, not just a compliance checklist.
— Chris
Where EnerlyticsAI Fits Into Certificate Reconciliation
Reconciling certificates against real consumption is tedious work when you're doing it site by site in spreadsheets. Enerlytics AI closes that gap with half-hourly consumption analytics and automated bill validation that catch anomalies before they distort your reconciliation numbers.
For businesses managing multiple sites, that means certificate retirements can be matched against actual metered data rather than annual averages, and the resulting carbon reports cover Scope 1, 2, and 3 emissions in one place. The platform's multi-site management tools were built specifically so sustainability and procurement teams aren't stitching together separate spreadsheets per location. You can start on the free forever plan and manage multiple sites without any upfront cost, then move to a paid tier like Eco at £49 per month if you need deeper reporting features. Set up your first site and see how the reconciliation workflow runs against your own consumption data.
Where to Find Official Guidance
For primary-source detail beyond this explainer, Ofgem's REGO scheme page covers registry access and issuance rules. The Renewables Obligation supplier guidance details compliance deadlines, and the 2024–25 redistribution report shows how buy-out funds get redistributed each year.
Sources
- Renewable Energy Guarantees of Origin (REGO) | Ofgem
- Renewables Obligation: buy-out price and mutualisation threshold and ceilings 2026 to 2027 | Ofgem
FAQ
What is the current price of a UK Renewables Obligation certificate?
The buy-out price for the 2026/27 obligation period is £69.34 per ROC, set by Ofgem. This figure acts as a soft ceiling on what suppliers will pay to cover a shortfall in their obligation.
What is an energy efficiency certificate in the UK?
Energy efficiency certificates like EPCs rate a building's energy performance and are separate from REGOs and ROCs, which track renewable electricity generation and supplier compliance rather than building efficiency. Businesses managing both should treat them as distinct compliance streams with different registries and reporting cycles.
Are renewable energy certificates effective?
Ofgem's own data shows suppliers presented the large majority of their obligation through actual ROCs rather than buy-out payments in the 2024–25 period, which indicates the certificate market is functioning as intended rather than acting as a fallback. REGOs are more limited in scope. They're a transparency tool for disclosure, not a guarantee that physical renewable power reached a specific customer.
What can you do with a renewable energy certificate?
A REGO can be retired against a Fuel Mix Disclosure claim, used for carbon accounting frameworks like RE100, or traded to another party before retirement. A ROC can be presented by a supplier to meet its Renewables Obligation, or sold on the open market to a supplier that needs it.
How can businesses reconcile certificates against actual site consumption?
Matching retirements to metered consumption works best with half-hourly data rather than annual estimates, since monthly generation swings can otherwise get lost in an average. Enerlytics AI's emissions reporting tools are built to support that kind of site-level reconciliation for businesses managing multiple locations.