I think the correct answer should be by adding #31# phone number or look under Settings > Call Settings > Additional Settings > Caller ID . There you have Hide number, Show number, Default.( for android phones )
Normally, if you selecte Hide number, all your calls to anyone will remain anonymous ( your number wont show ). This way you can bypass a blocked list.
“#31#” as a dialed prefix will have different meanings in different countries and on different provider networks. Generally it means “Disable Caller ID” rather than something like “Hide number”.
If a block is set to reject a particular name (Caller ID), it can sometimes get past a block. But if the block is made against a specific number, it probably won’t help no matter what your country or network is.
Most service providers provide methods of personal call-blocking at the network level in addition to at the phone itself. Such blocks prevent calls from even being routed to your phone.
You can usually also block various kinds of spam and robo-calls. By doing so, you’ll probably also automatically block calls that use hidden numbers, effectively defeating attempts such as the “#31#” mentioned above.