You can raise a modification – or mod – when you want to propose a change to any part of the Grid Code. 

For more information, please contact [email protected]

Search for any current or concluded modifications by name or ID. You can sort mods by ID, name, status or date of update. Or filter according to status.

Modification status
ID Name Status Last Updated Sort ascending
GC0123 GC0123 Clarifying references to NGET and Relevant Transmission Licensees Implemented
GC0124 GC0124 Critical Friend review period for submission of new modifications Implemented
GC0111 GC0111: Fast Fault Current Injection specification text Implemented
GC0118 GC0118: Modification to the Grid Code to accommodate the recent Distribution Code modification to Engineering Recommendation P28 –Voltage fluctuations and the connection of disturbing equipment to transmission systems and distribution networks in the UK Implemented
GC0114 GC0114: System Operation Guideline: Prequalification Processes Implemented
GC0122 GC0122 - Amending references to NGET and the Company within the Grid Code following previous modifications Implemented
GC0120 GC0120 - National Grid legal separation changes to clarify Grid Code responsibilities and consequential changes Implemented
GC0112 GC0112: National Grid Legal Separation Grid Code changes to incorporate NGESO Implemented
GC0116 GC0116: Correction to the compliance dates included in modifications GC0100-102 for the Requirements for Generators (RfG) and HVDC European Network Codes and other minor housekeeping changes Implemented
GC0115 GC0115: Legal Separation housekeeping: NGET to The Company Implemented

More about modifications

Modification Tracker

Our Tracker gives you the latest details on current code modifications including the purpose and the stakeholders it affects, as well as panel comments and where it is in the review process. It is published on the 7th (or next working day) of each month.

Modification Proposal Form

If you're thinking about raising a modification, please get in touch with us. Our experts can give you advice on your Proposal, explain how the modification process works and help to answer any questions you may have. When we receive your Proposal, we'll check it through and work together to make sure it's easy to understand.

Calendar

Once you've been in touch and are ready to write your Proposal paper, send it to us by the monthly modification submission date which you can find on our Calendar.