Bring my mobile number?
Hi Elvispresley!
Of course you can keep your number! 
All you need to do, is obtain a PAC code from your current provider; once you have signed up with us, you'll then receive your 'Welcome Email' to indicate that your SIM/account has gone live and this process can take up to 2 working days from the SIM dispatch date. Pass that PAC along to us and we'll start the process of bringing your number over to us.
The port-in process takes up to 1 working day when processed before 6pm on a weekday or up to 2 working days when processed after 6pm to complete; there will be some disruption on the network in the meantime and we don't process ports of a weekend, but this is part of the process. You can use your existing SIM until the transfer is complete and you will know this as your current SIM will stop working. When this happens, pop in your Plusnet mobile SIM and you'll be good to go!
Hope this helps! - Rebeka