Pressing the volume up/down or on/off buttons on the side or top of the iPhone will silence the ringer/vibration of an incoming call. Pushing the on/off button on top of the iPhone twice will send an incoming call immediately to voicemail.

There are 2 ways to silence the ringer on an incoming call on an iPhone. The first way is to push either the volume up/down on the side of the phone or the On/Off button on the top of the phone. This will also stop the vibration of the phone if the ringer has been turned off. This is especially helpful if you have forgotten to silence your phone when in a meeting.

You can also send an incoming call straight to voicemail if you push the On/Off button twice.

For other ways to respond to an incoming call, see the tip on Setting Reminders or Auto-messages For Incoming Calls.