There are two aspects to business telephone etiquette in the workplace, the consideration that you show to your fellow employees while you’re on the phone and the consideration you show to the person you’re talking to on the phone.
Respect Your Coworkers
The office can be a deafening place, and nothing is more annoying than listening to one side of someone else’s telephone conversation. When you’re on the phone, speak as quietly as you can without impacting your ability to make yourself understood. In deference to your coworkers, never use speakerphone unless it’s absolutely necessary. You will instinctively speak more quietly directly into the receiver than when using the speakerphone option. When you leave your desk, turn off your ringer and let your phone go directly to voicemail so that your coworkers aren’t driven mad by the constant ringing of your phone.
Respect the Caller
Always answer your business phone with a polite upbeat manner, no matter how badly your day may have been going before the call. A gruff hello will immediately put the caller on the defensive and may lose you an important contact or sale. If you are going to put the caller on speakerphone, ask his permission beforehand and inform him of any other people who may be listening in on the call.
If you have voicemail on your business line, make your outgoing message as simple as possible and limit the available options. Callers don’t want to have to wade through 13 steps just to leave a message. Make sure to check your voicemail often and return calls as quickly as possible. Waiting until the end of the day or until the next business day could make the caller feel neglected and hurt your business relationship. If a caller leaves a message, reply with a phone call rather than an email or a text message, unless the caller specifies that it’s okay for you to respond via text message or email. Pay attention to any instructions the caller leaves in the voicemail, such as asking you not to call after business hours or requesting a return call only after you have certain information.
Do not share a contact’s personal cellphone number or home phone number with your coworkers unless you have express permission.
New York Magazine
The Ins and Outs of Office Etiquette
Office Etiquette Essentials