I used to be with British gas and left them to Join OVO. My savings are significant. After Joining OVO I asked thenm to fit smart meters which they did for free (They wait for you to ask however, even though all smart meters are being paid for by the Government). I also have the Hive system fitted so I can control my energy when not at home. With the smart meters fitted, there is no monthly readings undertaken by OVO, it's done on a daily basis and I am billed monthly (I can see each day how much I have used). Anyway, moving on. At any time I can ask for some or all or my credit to be paid back into my bank account. To date, since joining OVO I have had no request for additional payments. Why would they when they can see my real time usage.Following on from my home insurance moan. ( now resolved , much cheaper) British Gas wish to increase my monthly gas and electric bill by £20, purely on forecasted usage. I am already £155 in credit. They do this every flipping year and then I have to go to the effort of contacting them to try to leave it where it is. I have a smart meter being fitted soon which will allow me to adjust payments if my usage does go up. Well they can jog on.