Thank you for your post!
When you have a smart meter, it is still possible to receive an estimated bill. However, this does not necessarily mean that the entirety of the billing period is estimated as it did with the old, 'basic' meters. A more likely cause of this is a portion of your usage data not being available for this billing period. This period could range anywhere from half an hour, to a whole day. If you'd like to find out more about this bill specifically, you're very welcome to get in touch with our web chat team here.