In universal personal telecommunications service, the number that uniquely identifies a UPT user and that is used to place a call to, or to forward a call to, that user. Note: A user may have multiple UPT numbers, e.g., a business UPT number for business calls and a private UPT number for private calls. In the case of multiple numbers, each UPT number is considered, from a network vantage point, to identify a distinct UPT user, even if all such numbers identify the same person or entity. Synonym universal personal telecommunications number.