Only just realised my first gas reading was never submitted, it was estimated?

I’m moving out of my flat next week and so I was providing my final gas & electric readings, the last time I was aware that I produced them was August 2018, the rest have been estimated. When I inputted my electric reading everything was fine but when I entered my gas reading a notification appeared saying it looks wrong and I had to upload a picture for Bulb to check. I decided to look into it a bit myself as I was worried and looked at all our previous readings (obviously most of which were estimated) according to the list the first electricity reading was submitted in August 2018 (when I am 100% sure I inputted a gas reading as well) however our first gas reading says ‘estimated’ next to it. The estimated number for our gas meter in August 2018 was 5067, however when I look at the tenancy agreement from when I moved into my flat, there are pictures of the gas meter and it is already displaying 5299, so I assume Bulb will assume I’ve used that nearly 299 during the year (even though it was racked up on the meter before I was even a tenant in the flat).

Why was my first gas reading estimated when I’m 100% sure I inputted it? Is there anything I can do, like produce a copy of my tenancy agreement which clearly displays the gas meter reading from before we moved in to prove the reading is inaccurate? What should I do? I’m worried about my final bill being ludicrous because of how much gas it might look like I’ve used. I hope this makes sense and any and all help is much appreciated!

I'm worried about my final bill being ludicrous because of how much gas it might look like I've used.

The time to worry about that was every month that you were asked and expected to enter meter readings but didn’t bother.

This is just a forum for fellow customers, we can’t do anything to help. I’d suggest giving Bulb a call (or webchat) and describing the problem. Provide as much evidence as you can, and see what they say. Hopefully they will accept the meter reading with the dated tenancy agreement and you’ll be fine. If not, then I suspect you’ll just have to accept the large bill and take it as a lesson to take better care of your affairs.