Hi ​@DuncanL ,

You should check the Meter Readings too - NOT just the usage data.

If it appears to be dead, https://smart-meter-help.ovoenergy.com can usually diagnose the issue.

There was a large update yesterday for all the Jan 1 price changes which might well have delayed your data. 
I would check again in a few days to see if they’ve been restored. 

The meter reading seems to be ok but app is showing no usage and my cost for year so far as £0.00.  There is a meter reading showing for 1 Jan but although it says Smart beside it, it may be the manual reading (it’s the same figure) I submitted when I realised yesterday that there was a problem.  

If it’s zero for this year so far - that’s expected due to price cap stuff. The reading for the 1st January will also be for the previous day, which is intended behaviour.

Try again in a few days!

I will take BP Lightlog advice and wait a couple of days to see if it resolves itself.

Thanks, Blastoise,  I had thought it might be due to update but they usually resolve themselves later in the same day.  Perhaps I just need to be more patient.

Just checked, zero for this year here too.

Mine came back earlier this evening and everything looks to be working correctly again.

Yes, 01 Jan has been updated.