The annual July price change is driven by changes in the wholesale network charges levied by electricity distributors, which retailers pass on to end consumers in their bills.

Electricity distributors operate under a regulated monopoly—there is only one distributor for any property—and the regulations include that new network charges come into effect on 1 July every year.

Retailers generally change their retail prices at the same time or shortly after to accommodate changes to their wholesale cost base.

Since 2021, the July distributor price change also affects Victorian prices. Victoria previously had its distribution network price change and the resulting retail price changes in January each year.

All states in the NEM are now aligned with a July price change that will affect all plans from all retailers.

The changes can be simple pricing updates to existing plans, but retailers often take the July price change event as an opportunity to release new plans or to overhaul their suite of plans and prices completely.

It usually takes at least a week for all retailers to release their new plans and prices, and when they do, there's often a knock-on effect as some of them re-adjust their pricing in response to their competitors.

So pricing is in flux for the first week in July.

Bill Hero policy is to pause bill comparison until pricing has settled down across the market. This is usually in week 2 of July.