In reply to a post by RobertoS:

If your phone line is also with O2 then care is needed when migrating. Plusnet normally take the broadband first then the phone line about three weeks later. In that three weeks O2 may place a cease order on the line because your broadband has been migrated away. Things then get very messy and nerve-wracking.

Ideally you get Plusnet to place a SIM Provide order on Openreach right at the start. That should avoid any issues but is in itself a bit unreliable at the Openreach end.

It inevitably means the broadband migration is delayed until the phone line move, as instead of a MAC type system the phone line has to take a minimum of something like three weeks to allow the losing CP to contact you and check you want the move to happen. To avoid slamming.

I just went through the online-order process when ordering Plusnet FTTC. The line was previously with Sky.

They automatically chose to do a simultaneous provide. As you need an engineer for FTTC anyway, I don't see it as any delay.

Speaking to the seemingly very knowledgable engineer I had, he doesn't seem to think there are any issues with simultaneous provides anymore - especially with FTTC. His only gripe was that he often found himself having to nudge the engineer at the exchange to swap the line as somehow they seem to end up getting behind his schedule.