they use ANI, as they're toll free numbers you're dialing (which means they're already capturing ANI for billing purposes[1].) this is also why caller ID block

they use ANI, as they're toll free numbers you're dialing (which means they're already capturing ANI for billing purposes[1].) this is also why caller ID blocking (as provided by your telco) doesn't work when calling toll-free numbers. 1: https://en.wikipedia.org/wiki/Automatic_number_identification#Toll-free_numbers https://en.wikipedia.org/wiki/Automatic_number_identificatio...