Hello @Sammmm_123, Thank you for taking the time to reach out to us.
If you have a basic electricity or gas meter that's only read every two or three months, we estimate the monthly bill in between. When we don't have actual data to calculate your bills, we estimate your energy usage based on historical usage and seasonal activity. If the estimations are not in line with the energy usage the actual meter read adjusts the usage.
To avoid estimated bills, you can submit your own meter reading in the AGL app or My Account. Please head to https://www.agl.com.au/help-support/energy/meters-and-reads/reads/submit-a-meter-read for more information.
Kind Regards,
Natalie