Definition
Ported number
A number that has moved to a different carrier while keeping its original digits, breaking range-based carrier lookups.
Number portability lets subscribers switch carriers without changing their number. Because carriers are assigned number ranges, a naive lookup of a ported number's range returns its original carrier — not the current one.
Resolving portability live gives the real carrier, the true (possibly changed) line type, and sometimes a fraud signal, since rapid porting can indicate SIM-swap or port-out attacks.