GC0185: Grid Code Changes for Mandatory Frequency Response (MFR) replacement

NESO are launching a new response service (Real-time Dynamic Regulation) in 2026/27 to replace Mandatory Frequency Response (MFR). It is expected that the two products will run in parallel to 2029 to enable transition, before phasing out procuring of MFR.

Modification status:
Current - Proposal Raised
Last updated:
21 January 2026

Code Administrator Contact: [email protected] 

Governance Route: The Proposer has raised a modification and is seeking a decision from the Panel on the governance route to be taken.

Impacts:  ​Medium impact​ on Market participants and NESO.

Modification drivers: ​System operability, system security, efficiency and GB compliance.

Code modification proposed by:
Thomas Goss

Documents