With 200 million smart meters rolling out across Europe, the suggestion in recent studies of over-billing by some 500 % when meters are exposed to certain interference, threatens to undermine consumer confidence in this €45 billion EU mandated roll-out. This is particularly alarming as all erroneous meters were already tested and approved under the EU’s measuring instrument directive (MID). Field measurements are needed to capture the real-world interference that appears in typical houses, along with interference generated by the newest home appliances. This interference is highly complex and continuously changes severity, so new methods are needed to trigger its capture and to break the resulting waveforms into their constituent parts. This requires new mathematical algorithms based on the methods used to detect defects in cardiac waves or as used in computer recognition of images. The distilled interference must then be regenerated in the lab in a reproducible way and used to test all types of European smart meter under identical conditions to see if any meters give significant errors. This will require the development of new testbeds to generate the waveforms, which together with the most problematic interference, can form the basis of new normative testing methods for the MID. Interference immune “benchmark” meters are needed to resolve consumers billing disputes and can be selected from these tests.