On 18 May 2018, we released our final decision on TransGrid's transmission determination for the 2018–23 regulatory control period. We also published a fact sheet to accompany and summarise our final decision. Our final decision is set out in the Overview and accompanying attachments. As a number of issues were settled at the draft decision stage or required only minor updates we have not prepared all attachments. In these circumstances our draft decision reasons form part of this final decision.

We commissioned reports that we took into account when making our final decision.

We must publish certain models with our final decision for TransGrid.

Pricing methodology

On 31 January 2023, the AER published its final decision on transmission pricing methodologies with amendments for system strength pricing (approved amended pricing methodology). The approved amended pricing methodology supersedes the pricing methodology approved in the AER’s 18 May 2018 final determination. All other aspects of the determination remain as per the AER’s 18 May 2018 final determination.