Hi @Hugh54 , what sort of meter do you have?

If you could post a photo someone might be able to help

This is the photo I sent to OVO a couple of weeks ago. The meter can handle 2 rates but in my case Rate 2 is disabled. If you try to toggle between Rate 1 and 2 it only ever shows Rate 1. I suspect the installer just used whatever meter was to hand and configured it to single rate.

Further to my last. According to the Installation Guide, this meter defaults to single rate and has to be configured into two rate mode as part of the commissioning process.

That looks to be pretty heavy usage. 1500kWh in ‘a couple of weeks’ would suggest consumption of the order of 100kWh a day, or an average draw of more than 4kW 24 hours a day … Similarly, 100,000kWh over less than 5 years is pretty hefty. 

What do you see on your meter readings page on the web? Do they just stop on 3 December last, or are there truncated readings (e.g. 05011 instead of 105011)? 

Billing will have been put on hold if an apparent out-of-band reading came along: 5011 is lower than 99,999. Have support not been able to rectify this?

Our consumption is high. 3500 square feet on 3 levels all-electric (air source heat pump - never buy one!). No change to consumption since the old meter was replaced with the SMART meter. Monthly consumption varies from around 1200kWh in summer to 2800kWh in the depths of winter. And we are EPC Cat A! 

The meter only displays 5 digits so when it tripped-over the meter would have gone to zero - which it did. It then increments normally. OVO’s internal systems have added a leading ‘1’ to the tripped-over readings, which I quite understand - it’s sensible in fact. The meter reading history on website and App is therefore accurate and there should be no out-of range issues. I suspect OVO don’t fully understand how their automated systems work.

Wow - that is some consumption. 
I think the problem is probably no more digits available on their registers. They often log to 3 decimal places (unseen on the display but actually recorded) so I think they might need one of 2 options. 
If the meter (and their system) can be reconfigured to use 2 decimals, that would give some breathing space. Alternatively if they can go back to the roll over, a bill could be constructed and then start billing again from all zeros. 
Never seen this situation before

Would a (technically uneeded) meter replacement sort things out by resetting things on the account?

For a while (once billing is sorted) but at that usage rate, it will recur 

Can I butt in and ask about the heat pump please? What do you have and how are you running it? 

Bit annoying that my previous post hasn’t appeared here. However, what heat pump do you have, size, make, rads or underfloor etc? How are you running it? It shouldn’t be eating electricity if it’s set up properly.