I think that you are talking about your In Home Display (IHD).
That is not the Smart Meter, it shows you what your actual meter(s) are recording without you having to go and look at the meter(s).
The meters themselves will be fixed to a wall, or in a cabinet/cupboard, either indoors or outside.
Find your actual meters if you haven't already done so, and take photographs of the readings on their displays so that you have a record of them.
If this is a flat then they may be in your flat, or they may be in a communal 'meter cupboard' with all the meters for all the flats there.
The readings given by the agency would usually be the readings from when the previous tenant moved out.
However if was empty for a while before you got the tenancy those readings could be lower than the ones when you got the tenancy. Particularly if they have had workmen in.
That's one reason why you take your own photos of the meter readings when you get a tenancy.
(Just to be clear you are responsible for bills after you get the tenancy, not from when you move in if that is later).
As you appear to have smart meters that are communicating then OVO will be able to see exactly what the readings were on the day that the previous tenancy ended and whet they were on the day that your tenancy started.
But it's still good to have your own photos of them, just in case.
OVO will bill you from what the smart reading were on the day you opened the account, anything from before that is not your responsibility.
PS. 33000 to 20600 is going down, I'd guess that if you are remembering correctly then the tenancy pack has the wrong figure.
Possibly/probably from a different meter if there are a few together in a meter cupboard, it wouldn't be unusual for someone from the lettings agent to read the wrong meter.
PS, I would not worry about the readings showing on your account yet, they may be estimates and it’s a bonus if they are already Smart Readings.
It can take up to 6-weeks for things to settle down with a new account
