How much historic usage data is stored and retained by smart meters?

I’m told that DCC doesn’t retain any historic smart meter data readings. However, I am informed that the smar meter itself does retain historic data but does anyone know how far back data is retained?
I was also sent this:-
There is also a third party platform called Energy IP and as long as the meter is communicating, they will hold all the historic data….
Anyone know anything about them?
Reason for asking…. trying to get a grip on data loss/errors when an energy company goes bust and erroneous data gets picked up and acted upon by the new supplier, often with disasterous results!