john is absolutely correct, you have a menu option in the phone which would be under settings, phone or settings, calls in which you are able to set the phone to show caller id. As well you can dial *82 which will unblock on a per call basis. you are also able to log into online account and remove any blocking from inside there as well. If you cannot find there, call 611 and they will be able to assist. if you are after hours go to wireless.att.com and click on the support tab up near the logo and put your make/model of phone then look in tutorials under calling features.