Shelly
Works locallyShelly EM and Pro EM-50 with clamps on the meter tails, and the Plus Plug UK for single appliances.
We clip a Shelly's current clamp around the cable from your meter, and the hub reads the whole house from it every few seconds. No smart meter and no supplier account needed.
The monitor itself is wired into the mains beside your consumer unit, so we fit it, not you.