Android
Show or Hide Caller ID auf Android
Android does not control caller ID from a single system-wide switch. Instead, the value is stored on your SIM profile through the Caller ID setting under Additional settings. That is why the same phone can show your number on one SIM and hide it on the other if you use dual SIM.
By default this option is set to Network default, which lets your carrier decide whether your number is shown. Most carriers show it, so recipients see your number unless you switch it manually.
To change it, tap Phone ➔ Open the Menu ➔ Settings ➔ Calling accounts ➔ choose the SIM card you want to adjust (only shown on dual-SIM phones) ➔ Additional settings ➔ Caller ID. Pick Hide number to stay anonymous on every outgoing call, or Show number to always display it regardless of carrier defaults.
Some carriers block manual overrides for certain call types, such as international or emergency calls, so your number may still appear even after selecting Hide number. If that happens, contact your carrier since the restriction sits on their network, not on your phone.