There are many circumstances under which you wouldn't want to answer a phone call. Whether you are in an important meeting or a quiet theatre or simply don't wish to talk to a particular individual, you can send a call to voicemail. The person calling will have the option to leave a message, and you won't have to speak with him directly. You can make a phone call go straight to voicemail if you set your cell phone to do so beforehand. If the person is already calling, you can send him to voicemail, though he will hear a ring or two on his end first.
Turn off your cell phone. If your phone is powered off, all calls will be sent directly to voicemail. With most cellphone carriers, the caller does not hear any rings prior to voicemail picking up.
Hit the "decline" button when someone calls. Most cell phones feature a "decline" or "ignore" button next to the "answer" or "connect" button. On some phones, this button may read "clear" or "end." When you hit this button, the caller is sent directly to your voicemail. Neither you nor the caller hears any additional rings.
Reduce the volume on your cell phone. If you are receiving a call, you can stop your phone from audibly ringing by pressing the "volume down" button. You won't hear any further rings, and the caller will be sent to voicemail. The caller will continue to hear the specified number of rings prior to your voicemail picking up the call.
Forward your calls directly to your voicemail. Call forwarding is an added service you can get from your provider. When you forward calls, callers are sent directly to your voicemail. Generally, neither party hears any rings. Call-forwarding instructions vary from carrier to carrier. Be aware that forwarding calls incurs additional charges on your monthly bill.
Use a direct-to-voicemail calling service if you wish to reach someone's voicemail directly. Services like Slydial bypass rings and send you straight to an individual's voice mailbox. You must first dial the service's phone number, then enter the phone number you wish to reach. You'll then be sent directly to the person's voicemail. The service is free, though you are required to listen to an advertisement before you are put through to the voicemail.
You cannot forward a call while it is in progress.
Many people know when you are sending them to your voicemail, particularly if they call you often. They may have learnt the number of rings that normally occur prior to your voicemail answering. If you send them to voicemail before the standard number of rings have occurred, they will likely know that you have done so.