Smarthings gives different usage to IHD

I’ve linked the SmartThings app to my IHD.
Today at this point the IHD states we’ve used 0.34p and 3 kWH, the ST app says we’ve used 0.64p and 3 kWH today… how do I know which is correct and why do they differ when the app gets it’s data from the IHD??
I have the app on 2 mobile phones and they both give the same data.

Difference in applying daily standing charge and possibly also VAT.

If the IHD knows the data then why doesn’t it show the data rather than leaving ST to do it?
I hope that VAT and SC doesn’t double my costs as is being suggested.

That’s a good question. From reports on here it appears to be random as to whether you have an IHD that includes standing charge, or VAT, or both. I don’t know why Bulb don’t seem to have control over this.

Hard to say based on your given information. You’ve said the IHD says 0.34p for 3kWh. I presume you mean £0.34, or 34 pence, and not a third of a penny. So that’s 11.33 pence per kWh. That figure is low, so must be excluding VAT. With VAT it’s 11.9p per kWh, which is still low. Either you have a fabulous Bulb tariff available only to you, or something is wrong.

Nevertheless, if 3kWh were your total daily usage, then 34p + 20p-ish standing charge, means your SC would indeed pretty much double your total usage cost. You’ll almost certainly be using considerably more than 3kWh per day though.

Can you check if your IHD is showing the correct tariff?