phone number change and divert

[#1]

Hi, I have a bt line at my parents address which diverts to my mobile for business. I also have a home phone with plusnet line rental. I want to cancel my line with bt at my parents but still keep the number, so can I change my home phone number to the one from bt? Also how do I call divert to mobile from plusnet. thank you.

[#2]

Not sure that this is possible and, judging by some stories here, could be fraught with problems if it is!
Have you investigated VOIP instead?  You could port your BT number to a VOIP provider and set the divert up with them?  You'd then benefit from reducing the cost of the diverted call which, depending on call volume, could offset the porting fee and monthly charge (depending on provider of course!).
This way, your PN line isn't touched and there's no risk of it all going wrong 

[#3]

yes but I don,t want to be paying for 2 lines as I am now.

[#4]

Porting the number will cancel the BT line so that's 16 quid save per month.  VOIP providers charge around 20 quid to port the number and then from zero to a fiver a month 'rental'.  Calls to mobiles could be less than a penny a minute...

[#5]

Would I still keep the same number and can it be diverted to mobile?

[#6]

Porting your number means that you keep the number, but use it with a different provider.  Some example providers:
www.voipfone.co.uk
www.localphone.com
www.vonage.co.uk
www.voiptalk.org
www.voicehost.co.uk
www.tamartelecommuncations.co.uk
A lot of these have dashboards that allow you to setup diverts very easily.  If all you want to do is use the divert, no further hardware is required but if you also want to use standard phones you'll need an interface box (ATA) or IP phones.  Note that you could avoid the divert completely by running a VOIP client on a smart phone but i don't know how reliable that would be.
I use Sipgate for incoming calls and Localphone for outgoing, with Asterisk running on a Raspberry Pi to glue it all together.  I ported my BT number to Sipgate but you can't do this on their basic residential account any more.