Balance Givenergy report to Octopus Bill

Has anybody had issues balancing there usage as reported by the Givenergy system to usage submitted by Octopus. I understand that there will be slight differences ( +-2) but we are seeing large numbers. Any thoughts would be very helpful.

Trumper More details would be helpful.
There seem to be two ways that GE reports energy: either by interpolating snapshots of power, or by using the 'meter data' readings from the inverter. The latter are possibly more accurate.

Trumper What's "large numbers"?

The meter (EM115) GE use isn't certified and is usually between 10-15% out on import compared to two certified meters on my install. Always has been. Pretty much accurate on export though.

Vestas

Claims it's MID certified (with a solid core CT clamp, admittedly)
https://givenergy.co.uk/wp-content/uploads/UK-Datasheet-EM115-Meter.pdf

rjp Its not "MCS certified" so cannot be used for billling purposes. ie its not very accurate on import.