24 June 2025

Find out about UNC Modification 0897S and the how it changes the way charges are calculated in the Gemini System.

On Tuesday 1 July, we’ll be delivering UNC Modification 0897S - Removal of Non-Obligated Entry Capacity from Capacity Neutrality Calculation. This change delivers updates to the Gemini System to change the way charges are calculated, specifically removing non-obligated entry capacity from the Capacity Neutrality calculation.

UNC Modification 0897S is scheduled to take effect from Gas Day 1 July 2025. Please note that invoices for July gas days will be generated in August.

There are no impacts to Gemini screens or APIs – this is strictly a calculation-only change.


Further information about UNC 0897S

The change has been approved by the Change Management Committee, and the associated Change Pack 3373.2 has been formally endorsed for delivery.

You can find more information about this modification on the Joint Office of Gas Transporters website.

Find out more


We’ll share an additional update following the successful implementation of this change.

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