I got chatting to someone involved in the SmartMeter roll out for one of the Big Six. He told me that the company handling the data via the GSM network is a single monopoly to provide equal and fair access to all market participants. This is mandated by legislation as far as I'm aware.
This is true. I work for one of the Big 6 and can probably elaborate on this a bit more.
Due to each supplier having their own contracted meter operators who install meters for them. EG G4S, UPLD, BGlobal metering etc etc to name a few there are a vast number and variety of meters out there. Currently if you move suppliers and the new supplier doesnt have a contract with the installing meter operator then it reverts to a dumb meter and you lose the functionality.
From this some legislation was passed and a third part Data Communications Company (DCC) is being set up and built up so that they will hold access to any smart meter regardless of who installs it and they then feed the readings they collect to whoever your supplier is at the time. I believe its meant to come on line later this year.
The first generation of "Smart meters" are classed as AMR/ SMETS1 meters and don't conform to the latest standards to be used by the DCC when its running so you may find a fair whack of these AMR meters installed from about 2008 onwards are non compatible and a compatible SMETS2 smart meter will be installed if the existing one isn't compatible.
I know my employer are now focusing on installing SMETS2 SMART compatible meters currently and going forward and I believe the big 6 suppliers are now doing this.
Useless fact of the Day your meter number will tell you the year of manufacture of the meter and generally whose meter it is.
eg E12Zxxxxx is a 2012 meter installed by Accu read/G4S, E15UPxxxxx is a 2015 meter installed by UPLD