Annual data requirements relating to service performance are specified in the Annual Information Order - electricity distributors 2024-25 to 2027-28 (the Order).

During our consultation on the Order, we received feedback from DNSPs recommending the AER share its S-factor calculation model, so DNSPs could see the inputs and calculations the AER use. DNSPs stated visibility over this model would allow them to explore reasons for different S-factor outcomes.

In response to this, the AER developed the S-factor calculation model in consultation with the DNSPs. Following two rounds of consultation with the DNSPs in December 2024 and again in June 2025, we published our S-factor calculation model and supporting handbook.