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v4.2Current version

Published25/08/2026Effective date31/03/2027Release date25/08/2026

Product definitions

Document Summary

What? This rule sets out the 5 standard DNO products (with 12 variants)How? Core parameters are used to define products. 12 variations of products are defined using those parametersWho? This rule impact DNOs and how they define products. In turn this impacts the products available to Flexibility Service Providers. It does not cover NESO productWhen? This rule comes into force in May 2026Why? This rule aims to reduce the variation in procurement across DNOs to simplify access, and improve market coordination

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Product definitions - Flexibility Market Rules - Elexon

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0.0

Sections 1, 2, 3 and 4 form the legally binding Flexibility Market Rule.

Defined terms capitalised in this document shall have the meaning given in Section 4.

GuidanceSummary of Product Definitions Flexibility Market Rule

This section is provided as guidance to the Flexibility Market Rule. Therefore, it is not legally binding and falls outside of the formal change management process.

Context

This rule establishes a standardised set of flexibility products for Distribution Network Operators (DNOs), aiming to reduce procurement variation and improve market coordination. It comes into force in February 2026.

A product, alongside it’s variants, defines what a System Operator is procuring. Adding further details like who is procuring it and when/how they are procuring creates an individual Sub-market.

By aligning product definitions, the rule simplifies access for Flexibility Service Providers (FSPs) and supports interoperability across DNOs.

Product Definition Requirements

The rule defines five core DNO products and twelve variants using a structured set of parameters including payment structure, availability mechanisms, and utilisation expectations

All DNOs must use the five standard products and their defined variants for at least 80% of their tendered and procured volume.

DNOs must confirm the products used across their sub-markets back to the Market Facilitator, who will track the procured and tendered volumes via data the DNOs have already published in accordance with License condition 31E.

We believe the impact of these requirements to be:

Impact on System Operators	Impact on FSPs
SOs must align product definitions and limit use of non-standard products. They must report implementation status and catalogue data.	FSPs benefit from simplified access and consistent product expectations across DNOs.

Implementation monitoring requirements

The key requirements are laid out below. A view across the rules is available in our deadline tracker.

Category

Requirement

Trigger for data submission

What we will do with it

Implementation tracking

Basic tracking of implementation status and target date

31/08/2026 (20 working days after the published date).

Track whether implementation is on track via our Implementation tracker.

Flexibility Market Catalogue data

Confirmation of product use and parameter alignment

Within 10 days of change

Provide an overview of the sub-market and the market as a whole via the Flexibility Market Catalogue.

Effectiveness monitoring data

KPI tracking use of standard products in tenders and contracts

21/06/2027 (15 working days after the first Reporting Period)

Monthly reporting via data submitted for FMR-DDR

Assess market alignment and identify areas for improvement via our Effectiveness Monitoring Report

Derogations against this rule

The following derogations are in place:

Who	What	For how long	Why
SSEN	The full requirements for LMA Interim Payment Service	Until 01/02/2027	To prevent blockers to LMA Interim Service settlement

1Applicability of this Flexibility Market Rule

1.0

This Flexibility Market Rule applies to all System Operator Sub-Markets within the Market Facilitator’s scope. Innovation trials are not bound by this Flexibility Market Rule.

All System Operators shall provide the data set out in section 3 no later than the timings also set out in section 3.

Variations to this rule are only permitted with an approved Derogation from the Market Facilitator.

The core dates for this Flexibility Market Rule are laid out below.

Table 1: Flexibility Market Rule dates

Published Date	25/08/2026
Implementation Date	31/03/2027
End Date	-

2Product Definitions

2.1Product definition parameters

The parameters that define a Product are:

Table 2: Product definition parameters

Purpose	Parameter Name	Description	Options
Structure	Payment structure	How the service is structured (i.e. what is the DNO asking of the Flexibility Service Provider)	Utilisation Only Availability and Utilisation
Structure	When Prices are set (procurement timescales)	Time before use that prices are determined	At Trade Operational
Availability	Availability request mechanism	How availability is requested from providers	Request initiated by DNO Request Initiated by Flexibility Service Provider
	Availability Acceptance timing	When availability is accepted by the DNOs	At trade After trade
	Availability Refinement timing	Can the DNO refine the availability required? If so, when. This determines what availability payments are due.	Yes No
	Availability changes allowed?	Can Flexibility Service Providers change their availability declaration post acceptance?	Yes No
	Minimum aggregate unit size	The minimum volume requirement for provision of availability	e.g. 50kW, 1MW, N/A
	Partial availability acceptance possible?	Whether the DNO can accept a portion of the offered volume	Yes No
	Time variable availability volumes allowed?	Can the Flexibility Service Provider provide different volumes for availability for the different periods within the availability window?	Yes No
	Availability Payment unit	The Units used for Availability Payments	£/MW/h £/MWh £/h
	Availability period	The unit of time considered for Availability Instructions	Electricity Forward Agreement (EFA) blocks Settlement Periods Minutes
Utilisation	Utilisation Payment unit	The Units used for Utilisation Payments	£/MWh £/MW/season
	Utilisation period	The unit of time considered for Utilisation Instructions	Electricity Forward Agreement (EFA) blocks Settlement Periods Minutes
	Delivery expectation	How the Flexibility Service Provider is expected to respond to a utilisation instruction	Continuous (a sustained delivery over the entire utilisation window) Peak Delivery (targeting the maximum response that can be delivered within the window) Maximum generation cap
	Maximum response time	Time from Utilisation Instruction to full output	N/A 15mins 2 mins
	Payments during response time?	Are Flexibility Service Providers paid during the response time	Yes No
	Minimum utilisation time	The minimum time a unit can be instructed for	60 minutes (Hour) 30 minutes (Half Hour)
	Minimum utilisation volume	The minimum volume that can be instructed	Measured in kW
	Utilisation instruction timings	Timeframes in which utilisation Instructions are communicated.	At trade Operational Real Time
	Partial utilisation instruction possible?	Whether the DNO can instruct a portion of the available volume	Yes No
	Time variable utilisation volumes allowed?	Can the DNO vary the utilisation instruction for the different periods within the availability window?	Yes No

2.2Standard DNO products

The five standard DNO products (Scheduled Utilisation, Peak Reduction, Operational Utilisation, Scheduled Availability + Operational Utilisation, Variable Availability + Operational Utilisation) and twelve variants are defined in the table below.

Table 3: Standard DNO products (and variants)

Purpose	Parameter Name	Scheduled Utilisation (SU)	Peak Reduction (PR)	Operational Utilisation		Scheduled Availability + Operational Utilisation				Variable Availability + Operational Utilisation
Purpose	Parameter Name	Scheduled Utilisation (SU)	Peak Reduction (PR)	2 min (OU-2)	15 min (OU-15)	2 min (SA OU-2)	15 min (SA OU-15)	Day ahead (SA OU-DA)	Week ahead (SA OU-WA)	2 min (VA OU -2)	15 min (VA OU-15)	Day ahead (VA OU-DA)	Week ahead (VA OU-WA)
Structure	Payment Structure	Utilisation Only	Utilisation Only	Utilisation Only	Utilisation Only	Availability and Utilisation	Availability and Utilisation	Availability and Utilisation	Availability and Utilisation	Availability and Utilisation	Availability and Utilisation	Availability and Utilisation	Availability and Utilisation
Structure	When Prices are set [procurement timescales]	At trade	At trade	At trade	At trade	At trade	At trade	At trade	At trade	At trade	At trade	At trade	At trade
Availability	Availability Request Mechanism	N/A	N/A	N/A	N/A	Request initiated by DNO	Request initiated by DNO	Request initiated by DNO	Request initiated by DNO	Request initiated by DNO	Request initiated by DNO	Request initiated by DNO	Request initiated by DNO
	Availability Acceptance timing	N/A	N/A	N/A	N/A	At trade	At trade	At trade	At trade	At trade	At trade	At trade	At trade
	Availability Refinement timing	N/A	N/A	N/A	N/A	Not allowed	Not allowed	Not allowed	Not allowed	Week Ahead	Week Ahead	Week Ahead	Month Ahead
	Availability Changes Allowed?	N/A	N/A	N/A	N/A	No	No	No	No	No	No	No	No
	Minimum Aggregate Unit Size	-	-	-	-	-	-	-	-	-	-	-	-
	Partial Availability Acceptance Possible?	-	-	-	-	-	-	-	-	-	-	-	-
	Time Variable Availability Volumes Allowed?	-	-	-	-	-	-	-	-	-	-	-	-
	Availability Payment unit	N/A	N/A	N/A	N/A	£/MW/H	£/MW/H	£/MW/H	£/MW/H	£/MW/H	£/MW/H	£/MW/H	£/MW/H
	Availability Period	N/A	N/A	N/A	N/A	Settlement Periods	Settlement Periods	Settlement Periods	Settlement Periods	Settlement Periods	Settlement Periods	Settlement Periods	Settlement Periods
Utilisation	Utilisation Payment unit	£/MWh	£/MWh	£/MWh	£/MWh	£/MWh	£/MWh	£/MWh	£/MWh	£/MWh	£/MWh	£/MWh	£/MWh
	Utilisation Period	Settlement Periods	Settlement Periods	Minutes	Minutes	Minutes	Minutes	Minutes	Minutes	Minutes	Minutes	Minutes	Minutes
	Delivery Expectation	Continuous	Peak Delivery	Continuous	Continuous	Continuous	Continuous	Continuous	Continuous	Continuous	Continuous	Continuous	Continuous
	Maximum Response Time	N/A	N/A	2 mins	15 mins	2 mins	15 mins	N/A	N/A	2 mins	15 mins	N/A	N/A
	Payments during response time?	No	No	No	No	No	No	No	No	No	No	No	No
	Minimum Utilisation Time	30 mins	30 mins	30 mins	30 mins	30 mins	30 mins	30 mins	30 mins	30 mins	30 mins	30 mins	30 mins
	Minimum Utilisation Volume	-	-	-	-	-	-	-	-	-	-	-	-
	Utilisation Instruction Timings	At trade	At trade	Real Time	Real Time	Real Time	Real Time	Operational - Day Ahead	Operational- Week Ahead	Real Time	Real Time	Operational - Day Ahead	Operational- Week Ahead
	Partial Utilisation Instruction possible?	-	-	-	-	-	-	-	-	-	-	-	-
	Time Variable Utilisation Volumes Allowed?	-	-	-	-	-	-	-	-	-	-	-	-

Null values (-) indicate that there is no aligned requirements for this parameter across DNOs

3Market Information

3.1Implementation tracking

The DNOs must provide the Market Facilitator with the data set out in Table 4 for each Sub-Market in scope of this rule. The data provided should accurately reflect their implementation of the rule within each of each Sub-Market.

The expected values required for compliance are also set out in Table 4.

Initial data shall be sent no later than 20 working days after the Published Date of this Flexibility Market Rule.

Updates shall be sent as soon as reasonably practical, and no later than 10 working days after any changes to the values.

Elexon reserves the right to publish this data within its Implementation Tracker.

Table 4: Implementation tracking requirements

FMR-PD	Parameter	Required value (per Sub-Market)
Implementation Status	Dependent on date: Before Implementation Date: Not yet started, Implementing, Paused, Implemented Between Implementation Date and End Date: Implemented After End Date: Superseded
Target Implementation Date	No later than Implementation Date

FMR-PD

Parameter

Required value (per Sub-Market)

Implementation Status

Dependent on date:

Before Implementation Date: Not yet started, Implementing, Paused, Implemented
Between Implementation Date and End Date: Implemented
After End Date: Superseded

Target Implementation Date

No later than Implementation Date

3.2Flexibility Market Catalogue data

The DNOs must update the Market Facilitator with the data set out in Table 5 below for each Sub-Market in scope of this Flexibility Market Rule. This should accurately reflect their implementation of each Sub-Market.

The expected values required for compliance are also set out in Table 1.

Initial data shall be sent no later than the Implementation Date of this Flexibility Market Rule.

Updates shall be sent as soon as reasonably practical, and no later than 10 working days after any changes to the values.

System Operators shall also publish this information themselves.

Elexon reserves the right to publish this data within its Flexibility Market Catalogue.

Table 5: Sub-Market definitions

Parameter	Description	Required values
Product	Which product is in use within the Sub-Market	Scheduled Utilisation (SU); Peak Reduction (PR); Operational Utilisation - 2 min (OU-2); Operational Utilisation - 15 min (OU-15); Scheduled Availability + Operational Utilisation - 2 minutes (SA OU-2); Scheduled Availability + Operational Utilisation - 15 minutes (SA OU-15); Scheduled Availability + Operational Utilisation - Day ahead (SA OU-DA); Scheduled Availability + Operational Utilisation - week ahead (SA OU-WA); Variable Availability + Operational Utilisation - 2 minutes (VA OU-2); Variable Availability + Operational Utilisation - 15 minutes (VA OU-15); Variable Availability + Operational Utilisation - Day ahead (VA OU-DA); Variable Availability + Operational Utilisation - week ahead (VA OU-WA);
Each parameter set out in Table 3. This should confirm the implementation of the products as defined and confirm the status of the parameters where no aligned values are currently set.

3.3Effectiveness monitoring

The following metrics shall be used to assess the effectiveness of the rule.

The DNOs must provide the Market Facilitator with any Additional Input Data as set out in Table 6 below for each Sub-Market in scope of this rule. The data provided should accurately reflect their implementation of the rule within each of each Sub-Market.

The expected values minimum required values for compliance, if any, are also set out in Table 6.

Initial Additional Input Data shall be sent no later than 20 working days after the Implementation Date of this Flexibility Market Rule.

Additional Input Data shall be sent in accordance with the Cadence set out in in Table 6.

Updates to Additional Input Data shall be sent as soon as reasonably practical, and no later than 10 working days after any changes to the values.

Elexon reserves the right to publish this data within its Implementation Tracker.

Table 6: Effectiveness monitoring metrics

Metric 1	Description	Percentage of DNO tenders in reporting year using standard products
	Why are we tracking this?	To understand the volume of standard products being put out to the market by the DNOs
	Cadence	Monthly
	Data source	Existing Data – DNO Data Reporting Rule: Total Tendered in Reporting Period (Sum of standard products/Sum of all products) Additional Input Data - None
	What does good look like	100%
	Minimum Requirement	>80%
Metric 2	Description	Percentage of DNO contracts in reporting year using standard products
	Why are we tracking this?	To understand the volume of standard products being bought from the market by the DNOs
	Cadence	Monthly
	Data source	Existing Data - DNO Data Reporting Rule: Total Contracted in Reporting Period (Sum of standard products/Sum of all products) Additional Input Data - None
	What does good look like	100%
	Minimum Requirement	>80%

4Glossary

4.0

The following definitions are specific to this Flexibility Market Rule. These are supplemented by the definitions in the Market Facilitator Glossary. If there is an inconsistency between definitions, the definition in this document shall prevail.

Glossary

Term	Aliases	Definition
Continuous	-	a sustained delivery over the entire utilisation window
Peak Delivery	-	targeting the maximum response that can be delivered within the window
Reporting Period	-	in respect of data submitted under section 3.4 of FMR-DDR, the period of time to which the submitted data should relate. The first Reporting Period shall be 01/04/2027 to 31/05/2027 inclusive. Each subsequent Reporting Period shall be a calendar month, beginning on the first day of that month and ending on the last day of that month. More frequent submissions by a System Operator shall not create additional Reporting Periods.

FMR: Product Definitions - Amendment record

Guidance

This section is provided as guidance to the Flexibility Market Rule. Therefore, it is not legally binding and falls outside of the formal change management process.

Version	Published Date	Document Status	Description of Changes	Change Proposal Reference	Market Facilitator Decision Report Ref
1.0	12/12/2025	Final	Document Published
2.0	04/02/2026	Final	Housekeeping changes	CP002	CP002
2.1	17/02/2026	Final	Derogation Rule added
3.2	12/05/2026	Final	Revision of the Rule	CP003	CP003
4.2	25/08/2026	Final	Revision of Implementation Monitoring Requirements	CP005	CP005

4.0.2

Annex 1: Associated meta-data

Guidance

This annex is provided as guidance to the Flexibility Market Rule. Therefore, it is not legally binding and falls outside of the formal change management process.

Identifier	FMR-PD
Title	Product definitions
Type	Flexibility Market Rule
Collection	Sub-Market Alignment
Audience	DNOs, Flexibility Service Providers
Expertise	Market Design
Owner	Market Facilitator
Expected benefit	Deliver aligned flexibility Products across DNOs to: - reduce variation across DNOs - simplify access for Flexibility Service Providers
Related end-to-end process reference	E.1 Define Sub-market
References	FMR-SMD, FMR-DDR
IsReferencedBy	FMR-SMD, FMR-SBM
Published version number	4.2
Applicability	All DNO Sub-markets
Published Date	25/08/2026
Implementation Date	31/03/2027
End Date	-
Terms of variations	Approved Derogation
IsReplacedBy	N/A
Replaces	N/A
Status	Final
Change since last version	Revision of the Rule
Description	What? This rule sets out the 5 standard DNO products (with 12 variants) How? Core parameters are used to define products. 12 variations of products are defined using those parameters Who? This rule impact DNOs and how they define products. In turn this impacts the products available to Flexibility Service Providers. It does not cover NESO product When? This rule comes into force in May 2026 Why? This rule aims to reduce the variation in procurement across DNOs to simplify access, and improve market coordination