A mixture of both.
Your calling circle will be added and anyone you have phoned at least twice in the last 35 days.
You can add numbers via my account, but I found it easier to wait until someone phoned me and then pressed 1 to accept the call. This number is then automatically add so your caller will not need to announce themselves again.
There are also national whitlist numbers such as banks and NHS who can also phone without announcement. Sometimes this list is not up to date but the will announce themselves, scammers will not.
If you have any doubts on who is announcing themselves you can press 2 to accept for one occasion only, and the caller would need to announce themselves again.
There is a faq page in the knowledge bank for further reading if you wish
https://community.talktalk.co.uk/t5/Articles/About-CallSafe/ta-p/2204784
Please remember to mark Solved Posts with Best Answer. Doing so helps other customers and saves TalkTalk's Support Team time by only looking at unsolved topics. Thanks, Steve (a fellow customer).
