Smart: A guide to SMETS1 and SMETS2 smart meters
How to tell which smart meter you have
The rollout of SMETS2 meters began in 2018. If your meter was installed before then, it’s likely to be a SMETS1-type meter.
Because suppliers continued using their stocks of first-generation meters after 2018, it's possible you have a SMETS1 meter, even if it was installed more recently. Nothing wrong with that, if so. SMETS1 meters have all the same energy-saving features as SMETS2. The main issue is simply one of ensuring they continue to be ‘smart’ if you ever decide to change supplier.
The easiest way to tell is to look at your electricity meter. If the serial number starts with 19P, this indicates it's a SMETS1 meter. If it starts with 19M, then this means it’s SMETS2.
Another way to tell is to look for a Telefonica/Arqiva/WNC/Toshiba device with two to five LED lights on top of your electricity meter. If you can see one, then you have a SMETS2 meter!
However, to be 100% sure, the best way to find out which type you have is to contact the supplier that installed it.