I have just moved to Octopus from Scottish Power. The reason is somewhat complicated, but Scottish Power customer service was civil enough but unhelpful, hadn't turned up on an appointment date and, in the end, stated they couldn't provide what was requested. Octopus, via the customer service guy, Amman, was everything you could hope for in dealing with a change via a large company. Extremely helpful and knowledgeable, explaining details in a very clear and concise manner, promising to provide what was requested, and giving me confidence that the change-over would be smooth and without difficulty. I had heard good things about Octopus Energy from a couple of friends and that is why I chose them when I needed to move from Scottish Power.