How report and block a private number?

[MollyAberdeen21]

I've had a private number call me and I believe they were fishing for voice recording they could use.  How can I report this number and have it blocked from ever calling me again?  The usual options don't apply because it's a private number.

[Manatarms84]

As far as I understand would be to block withheld numbers but that can be problematic as there are a lot of places like doctors and hospitals which won't hold numbers.

You could perhaps try blocking international calls as a lot of these calls come from overseas.  You can log into your online BT account and manage your phone service from there or call BT and they can do it for you.  I had a small issue with spam numbers even with call protect but since blocking international numbers they have all but stopped

[edbostan]

Use Call Protect. Its a free service and you dial 1572 which gives options to block numbers. 

[JWS]

Have you considered a call blocker phone with trueCall built in? You need Caller Display enabled on your line (free I believe now, used to be a nominal charge) and then any caller not in your phone book is forced to announce themselves before your phone even rings. In the years we’ve had ours only two sales calls have had the cheek to announce themselves! You can check your logs to see how effective the service is. Works far better than I’d ever imagined it would. 

[licquorice]

Indeed, blacklisting is futile, the list of numbers is infinite. The only sensible option is whitelisting.