Utility bills can usually be paid by monthly direct debit or quarterly.
If you pay quarterly, your bill wil be based on usage.
If you pay monthly, the company will estimate how much they think you should be paying over the year, based on your previous usage, and then even it out so you are paying pretty much the same amount each month. They will check your usage periodically and if it goes up or down, they will adjust your monthly bill accordingly (notifying you in advance, of course.)
You will still get quarterly bills (my water company bills semiannually), so you can check them and see if there are any errors.
I switched from quarterly to monthly billing recently and I find it is much easier to budget.
The company will provide you with a bill so you can check for mistakes.