Cheers for that info. I was taught, in a course I did, that part of the MAC - migration access code that is - comes from numbers in the router. Perhaps it is a combination of some of the numbers in one, for instance the first numbers and letters of your examples. I don't see how, though, because it would have to change with each ISP you use that router for and that would be quite hard to do, unless the ISPs can view the details in your router when you apply for it. I'm sure that's not impossible for them to do. I'm thinking, now, however, that the course info was wrong - or, as you said, right for those ISPs who force you to use their hardware only.