Open your Phone app

Tap on the three dots in the right hand corner

Tap Settings

Tap on Calls (or Supplementary Settings if using a Samsung device). If you don't see one of these options, look for a More settings or Other Call Settings option

If you see an Additional Settings option please tap on it, if you don't have this option you can skip this step

Tap on Show Caller ID or Caller ID (Please note that this option may have a slightly different title depending on your device)

Tap on Hide Number or Never (This option may also have a slightly different title depending on your device)