This question sounds a bit clandestine. But in an age of mobile phone and spam phone calls, many of us are concerned about widely sharing our mobile phone numbers.

Several months ago I wrote a column for the Oklahoma Bar Journal Text Messaging for Lawyers. In it, I mentioned ZipWhip, an enterprise texting service that allows one to use their app to send and receive text messages on a mobile phone without revealing the phone number. There are other similar services.

But, there is a free method that allows you to block your number from being displayed when you place a call. Simply dial *67 before you dial the number. The recipient’s caller ID will display your call as “Private” or “Blocked.” Of course, today that means many will not answer the call and you will have to decide whether to leave a call back number or not.

For more ideas along this line, including setting up your phone to not share your number on any calls, read 5 ways to block or hide your number when making calls by Kim Komando in USA TODAY.