On 26 May 2025 the AER released its final determination on the Default Market Offer (DMO) prices for financial year 2025–26.

ACIL Allen supported us in the design of a forecasting approach for wholesale and environmental costs.

The report Wholesale energy and environment cost estimates for DMO 7 final determination by ACIL Allen was published alongside the final determination.

We have published a spreadsheet of ACIL Allen’s modelling data for the cost of energy for interested stakeholders to understand its forecasts. The information contained in the modelling data is also set out in the ACIL Allen report for our final determination.

On 26 May 2025 we released the model for calculating DMO prices for 2025–26.

As set out in the DMO 2025–26 final determination, our approach is to use a cost build-up approach to calculate DMO prices, taking into account forecast costs for wholesale electricity, network, environment and retail costs. The model calculates the expected changes in these costs for 2025–26 for each area and customer type.

The information contained in the model is set out in the DMO 2025–26 final determination. We have published the model to provide stakeholders with additional transparency on how we calculated the DMO prices for 2025–26.