Best answer by Gray4276
Welcome to the Community Forum for PP customers.
You have actually been "over conscientious", honestly!
The date contained within the email "prompt" from PP is the date to use if you don't want an estimate on your statement.
This date is the accounting date for your account, and PP will have to estimate the difference from your submission to the accounting date. If you look in your App under Usage and check your "readings history" you will see your reading as an "actual" reading followed by the "estimated" reading by PP.
The difference will not be much, and will even itself out on your next meter reading submission. So try to submit on the "date" and not before if possible.
Hope that helps