Changing to fibre and landline will plug into router, what about second phone, will that work?

[Caroline23red]

I am just about to change my Sky broadband to fibre as it has recently been installed in the area.  I realise my DECT landline phones x 2 will no longer work plugged into the phone socket and will have to be plugged into the router, however, will the additional handset I keep upstairs (which plugs into the electrical three pin socket) still work?

Also, will the phone plugged into the router still be able to receive answerphone messages?  It has a built in answer machine?

I don't really understand why a line rental has to be paid when the phone is running via the broadband, I have read on the forum that a charge for phone is required if you are using a landline.  

If I decide later to no longer use a landline, can I cancel my charge for the line with Sky?

Thank you

[Highlinder]

@Caroline23redIf the base station for the phone upstairs is the one that you have plugged into the router, then the other phones should work without issue.

Your phone package if it is the same as you had before, it will work just the same.