Markets Data Definitions for Energy Suppliers
Summary
Ofgem published the Markets Data Definitions, a transparency document providing high-level terminology definitions for energy suppliers submitting data to Markets collections. The document supports consistent interpretation of data requests but explicitly does not introduce new requirements, replace guidance, or override licence conditions.
What changed
Ofgem released the Markets Data Definitions guide (publication date 2 April 2026), establishing standardized terminology for energy suppliers interpreting data requests across Ofgem Markets collections. The document provides definitions for key data terms but explicitly states it is explanatory only, acts as a supporting reference, and does not override collection-specific guidance or licence conditions.
Energy suppliers should use these definitions in conjunction with individual data collection guidance rather than in isolation. No compliance deadline or new obligations are introduced. The definitions will be updated periodically based on regulatory changes and user feedback, with contact for queries at MarketsDMO@ofgem.gov.uk.
Source document (simplified)
Markets data definitions
Publication type: Transparency document Publication date:
2 April 2026
Topic: Financial resilience Print this page
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- High-level data definitions to help suppliers and Ofgem teams interpret data requests consistently. They support clarity and do not replace guidance.
Purpose of the Markets data definitions
The Markets Data Definitions are designed to help users understand and interpret the terminology used in Markets data collections. They aim to:
- explain key data terms used across Markets collections
- support consistent interpretation of data requests
- improve clarity and comparability of information submitted to Ofgem These definitions act as a supporting reference. They complement—not replace—the guidance for individual data collections.
Using the definitions with data collection guidance
Always use the Markets data definitions together with the guidance, templates and instructions published for each data collection.
The definitions do not introduce new requirements.
They should not be used alone when preparing or submitting data to Ofgem.
Important information
The definitions are high level and explanatory.
They do not override licence conditions, statutory guidance or the specific instructions for an individual data collection.
If there is any difference between a definition and collection specific guidance, the collection specific requirements always take precedence.
Governance and updates
All definitions are reviewed and approved through Ofgem’s Markets data governance processes before publication.
The dictionary will be updated periodically, based on regulatory changes and user feedback.
Contact
Please contact MarketsDMO@ofgem.gov.uk for further information.
Documents
Markets data definitions [XLSX, 48.20KB] Print this page
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