Hi @stephenl sorry for the delay, this is more of a discussion forum than anything else so we don’t necessarily respond to queries here as fast as over email, chat or phone. I would say that this is because of a relatively recent change in your annual consumption (of gas, specifically). For every meter in the uk, there’s a government body that keeps up to date annual consumptions of gas and electricity (in kWh), which they provide to your new supplier when you switch over and which they update every time we send them one of your meter readings. We get updated versions of these annual consumptions every month or so, and they’re the ones we use for your estimated yearly usage and so on.
Looking at your account, it appears that the most recent annual consumptions we’ve received for you are a bit higher than the ones we received when you switched over, suggesting that your usage has risen a little. I don’t want to put the exact details up on a public forum, but we can give you the exact numbers if you get in touch through some more private channel. Regardless, I think that these higher estimated consumptions make up the difference. If it turns out that you aren’t using more over the course of the year than in previous years, and that whichever readings led to those higher annual consumptions were just one offs, then those consumptions (and thus your estimated usage) will go back down again.