Unrecognised callers are blocked with a screening announcement that gives them an alternative method of getting in touch:
“Hello - I only accept calls from friends and family members. If you do need to get through please call Alex on 07767 xxxxxx – or enter your code now”
Legitimate callers can make contact via Alex- telemarketers and scammers hardly ever do this.
Sometimes legitimate callers will call from lines where their number is withheld. These callers can enter the Access Code to get through. Each trueCall Secure SIM is issued with a random three digit Access Code, but you can change this at the Internet Control Panel to something more memorable if you prefer.
This option gives 100% protection - only callers on the Allow list, or those who know the Access Code can get through.