New house / new connection

[#1]

I'm moving into a new house next month and I need to open a new broadband account rather than transfer an existing one.
It's quite important that I have internet as soon as possible as I do a lot of work from home.
I'm planning to get Plusnet fibre. When I create a new order it says there is already a line active there. There is.
I have two options, install a new line or take over the active line.
One of the conditions of the sale is the previous owner keeps the existing number, which is fine by me. So until they transfer their service out I can't order broadband.
Should I just create a new order with a new line installation? Plusnet want to charge me £40 for this which I'm happy to pay if it means getting my internet setup sooner.
If they come to install it and there is an existing line into the house will they create a new one - or if it's cancelled in time will they just use the existing line? Will it confuse the system if there are two lines?

[#2]

Hi there,
As there should be no reason to open a new account as part of a move of services our sign up process doesn't cater for this.
However we appreciate that the main reason for wanting to do this could be perhaps for an overlap in services or maybe a change of username?
If that's something you need us to do I'd advise giving us a call on 0800 432 0200 so we can go through this with you and take care of the leg work.