I need to block my number when making a call 67 is not working

If your carrier is AT&T, they indicate that *67 isn’t universally available:

https://www.att.com/support/article/wireless/KM1010535

https://www.att.com/device-support/article/wireless/KM1358182/Apple/iPhoneXR

and in at least some contexts, it’s #31# — per what is published, #31# appear more likely to work.

*67 is the landline code. #31# is the GSM (wireless) code.

KiltedTim wrote:

*67 does work for me on AT&T.

Per AT&T, *67 is not universally available in all markets, or some such wording. If it works, you can use it. Per what is posted, I’d likely choose to use the GSM #31# code and not the *67 code. See the AT&T links previously referenced.

elizabethfromcoral springs wrote:

I need to block my number when making a call.

settings - phone - show caller id - off

*67 does work for me on AT&T.

You said you tried 67. It should be *67. Did you use that?

Note that if you’re calling a “toll free” number, you generally can’t block your outgoing CallerID.