Three way calling is something that would be enabled within the settings of your handset, but there won't be any additional charges to UK Mobile numbers or Landline numbers, as they'll be included within your bundle.
However, if you happen to go over your call allowance, you will be charged our standard rate of 40p per minute.
You can keep check on your usage via My Account online, or you can call our friendly Customer Service Team by dialing 500 from your Plusnet SIM.
We also have a new feature available for Bundle Notifications and this allows you to receive an SMS daily or weekly with your bundle/ usage available. If this is something you'd like activating on your account, please don't hesitate to drop me a PM and I'll be happy to help. -Ashleigh