We have a requirement like below:
Person A (like an Agent) want to call user B with masked number. User B sees masked number (not the real number of A) and B can also call back to Agent with the masked number. At B side, normal telephone needs to work.
So, our conceren is, can we able to use the masked phone number for Agent with a real phone number so that B can call back Agent ?
We considered the option, Caller ID for agent, but the caller id verification needs to be avoided in this use case.
Please help.
We usually refer to these type of "masked" phone numbers as proxies.
Do agents call from a phone or using the Voice SDK?
If an agent calls from a phone.
You could build an application with a Twilio Phone Number that the agent can call. When the agent calls, the application could ask the agent to enter the user's phone number using the TwiML Gather verb, then the application can dial the entered phone number. As a result the user would see the Twilio Phone Number aka the proxy number, and not the agent's phone number. Depending on your needs, instead of asking for the user phone number, you could ask for the customer ID or other identifier that your application can lookup the user's phone number by. The user could call the proxy number, and your application could look up the associated agent's phone number from a database, and then dial the agent's phone number.
If you don't want the agent to enter a phone number or user identifier, you could acquire a Twilio Phone Number programatically for each Agent/User combination, then store the agent phone number, user phone number, and proxy number into a database. When the proxy phone number is called by the agent, your application can dial the user's phone number, when the user calls the proxy number, your application can dial the agent's phone number. Technically, other agents and other users could also be assigned to this proxy number, but you wouldn't be able to assign the same agent or user to the same proxy number multiple times as you wouldn't know which agent/user to dial when called.
If an agent calls using the Voice SDK.
Using the Voice SDK could be a better experience for your agents and also simplifies the solution somewhat. When you initiate a call through the Voice SDK you can pass along extra parameters to your application. So say that you have a web application that lists the users, and every user has a "call" button, you could click the button and the user's phone number could be passed in as a parameter to your application. Your application can then instruct Twilio to dial the user's phone number. When the user calls the proxy number, you'd still need to look up the agent associated to the user in a database and dial the agent's Client ID.
Unfortunately, I can only suggest these high level solutions with the information you provided, but I can provide more instructions if you provide more details.