My apologies if I jumped the gun a little in promoting Scottish Power before it was completely verified. In hindsight, perhaps it would have been better to wait until a switch was actually successful rather than reporting what was said verbally.
However, I have now spoken to them three times over the last few days and each time they have confirmed they will be able to supply economy 7 to an economy 10 meter. They have also made notes on my account confirming this. As a word of caution, I did speak to someone from ‘sales’ today who also denied that they were able to supply me (and seemed ignorant of what economy 10 was, insisting it involved ‘three rates’) – however I have since spoken to customer services who again confirmed that it was possible. They asked me to call back when I have the new meter to provide the number and take it from there – and also verified that the notes were present on my account confirming that they have promised to supply me. There seems to sometimes be some confusion at their company over the difference between supplying a distinct economy 10 tariff and economy 7 tariff to an economy 10 meter and I believe it is necessary to be clear with them (customer services rather than sales) that it is the latter that is required. Previously when a sales assistant has talked about ‘not supporting economy 10’ it appears to be the former that is meant.
I would also add that although their rates appear to be by far the cheapest, my experience of customer service at this company over the past 3 years has been mixed. As evidenced by the above, it has often been the case that the quality and accuracy of the service received appears to depend on the person you talk to (and their level of training). I would note that the overall level of service, in addition to the price and online services, have been enough to keep me with this company so far.
I will continue to attempt the transfer. Perhaps it will be best for others to wait until I report back with the progress of this and whether it has been successful. I believe the other tariffs I have posted on here are all correct (for example iSupply and others) and will all support an economy 10 meter. (If you do attempt to contact Scottish Power again I would suggest making sure to be connected to ‘customer services’ rather than ‘sales’, however I will crack on with this myself in the meantime and report back on my findings). Apologies for the confusion so far – and good luck with your search!