Packages increase in cost depending on whether you just want to call at Weekends, Weekends & Evenings or Anytime.
These usually include standard landlines (01,02 & 03) 0845, 0870 & most mobile numbers.
There is no guarantee you will get a VoIP line. Some areas are not enabled & still use standard landlines, & in areas where VoIP has been introduced as an addition this is usually targetting new customers.
As a Very Insightful Person, I'm here to share my knowledge. I don't work for Virgin Media.