I strongly suspect my water meter went from 199 to 300, not 200, my historical and present usage figures back up my assumption, and I have no leaks, I have tested this by not using any house water for some hrs for no reading. Local council will not agree. We live in SE Queensland

You can ask about the proper appeals process with them. There is really no way to prove it did this.

Knowing how the mechanisms work on these meters... (which is exactly like a mechanical odometer in a car)... it really is mechanically impossible for them to jump ahead like that. WHen they break they will stop moving on any of the digitis higher than where the fault occurred as the llowest digit is driven....with each successive digit driven through a 10:1 ratio gear from the lower digit.

I have no leaks, I have tested this by not using any house water for some hrs for no reading But what if the leak is in the service line between the house and the meter? Let's check. Shut down all the water in the house. Now go out to the meter and check the little pointer, t should not creep or mover. Let me know what you find. Good luck, Tom