The telephone numbers that are supplied with our O2 plan are REAL UK mobile numbers ( MSISDNs ) and not virtual numbers ( DIDs ) or PSTN numbers.
This means that they operate identically to any other mobile number e.g. they can receive Two Factor Authentication SMSs etc.
It also means that they can be ported to most other UK mobile operators – see our porting FAQ for details.
Our Travel plans are data only and do not have a phone number associated but calls can be made and received via all the popular Apps such as WhatsApp, Messenger, Telegram, Skype, etc.