Understanding proper telephone etiquette is an important skill to have no matter what you do professionally. Whether you're having a casual conversation with a friend or talking to someone on business, there are ways you can make sure you're being nice.
Steps
Part 1 of 2: Use Basic Telephone Etiquette

Step 1. Greet the other person politely
Whether you make or receive a call, be sure to say hello to the other person politely. Greet her as if you saw her in person. If you don't know her, introduce yourself as if you were meeting her in person for the first time. If you know the person you are calling, be sure to identify yourself before starting the conversation.
- A common friendly greeting when making a call can be something like "Hello, my name is … how are you?"
- If you answer a call, a common greeting can be something like “Hi, how are you? Thanks for calling".
- Read the tutorial How to answer the phone politely.

Step 2. Speak in a normal tone of voice
If you talk too loud on the phone, it can be uncomfortable for the person on the other end of the line. Similarly, if you speak very slowly, it can be difficult and exhausting for the person listening to you on the other side. By speaking in your normal tone of voice, you will avoid making your voice uncomfortable.
If you are worried about speaking too loudly or too slowly, say something like "Excuse me, do you hear me right?"

Step 3. Speak directly into the microphone of the phone
Even if you speak at a normal volume, the person on the other end of the line will have trouble hearing you if you don't speak directly into the phone's microphone. This is the intended use of the phone. Also, using the device properly will ensure that the other person can hear you well.
If there is a problem with the microphone, consider purchasing a hands-free headset to resolve the issue

Step 4. Don't eat while talking on the phone
One of the most disrespectful things you can do when talking on the phone is eat, drink, or have gum in your mouth. Telephone receivers amplify chewing sounds and it is disrespectful to allow the other person to hear these sounds. If you have a lunch planned and you're on the phone, wait for the conversation to end or ask the other person if you can call them when you're done eating.

Step 5. Eliminate distractions while talking on the phone
When talking on the phone it is important that you limit distractions as much as possible. If you are at home, turn down the volume of the music you are listening to and turn off the television. Know what else can distract you before making a call, and do your best to avoid these distractions.
If there are other people in the room, consider leaving or going to another room so that you won't be tempted to talk to them while using the phone

Step 6. If you have a bad signal, ask the person if you can call them back
If you are on the phone in an area with a poor signal, it is best to ask the person if you can return the call. Having poor reception issues can be disrespectful to the other person, especially if you have to stay in that area for some time. Kindly ask if you can call back at another time and apologize for the inconvenience.
A polite way to ask someone if you can call them back might be something like “Excuse me, I seem to have a bad signal. Can I call you back as soon as possible?

Step 7. Say thank you and say goodbye at the end of the call
It's nice to say thank you at the end of a phone conversation, but it's also important to say goodbye. Because there are no facial signs when talking on the phone, it is often difficult to tell when the conversation is over. By saying something like "Thanks for calling, see you soon!" it will be clear to both of you that the phone conversation is over.
If you want more information on how to politely end a phone call, read an article on the subject
Part 2 of 2: Talking on the Business Phone

Step 1. If you receive a call, answer the phone when it rings 2 or 3 times
If you get a business call, it's best not to keep the other person waiting. Being prepared for a scheduled call will allow you to answer it in an appropriate amount of time, and it will also give you time to eliminate any distractions that may be entertaining you.
If the call is not scheduled, it is not so important that you answer when the phone rings 2 or 3 times, but you still need to answer as quickly as possible,

Step 2. Greet the other person using their professional title
Address the person using their professional title (for example, Dr. Barrón or Dr. Robles) instead of calling them by name. This is business etiquette that is used in person, but should be taken seriously over the phone as well.
If you have the confidence to call the other person by name, it's okay to leave the formal title over the phone

Step 3. Identify yourself properly if you are the one making the call
When you call a person and they answer the phone, it is important that you identify yourself and tell them what you are calling for. This will eliminate any confusion on your side and ensure that the conversation is as efficient as possible.

Step 4. Use professional language
Avoid using jargon or profanity when representing your business or someone else's on the phone. Act like you're at work and use appropriate, professional language. If you are in doubt about whether something you want to say is appropriate, imagine saying it at work and anticipating whether the person you are talking to will take it well.
A good rule of thumb is to stay on the safe side and don't say something if you're not sure it's appropriate

Step 5. If you must, ask the person if you can put them on hold
Whether you work in the office or at home, distractions will inevitably crop up during a business call. If your attention must be elsewhere for a moment, it is appropriate etiquette to apologize and ask the person if you can put them on hold.
Make sure to use the phone's "on hold" feature to mute your side of the line. If you forget to do it, the other person will be able to hear you

Step 6. Be patient and try to be as helpful as possible
There are times when business calls can get a bit tense and staying calm is important as an appropriate form of telephone etiquette. If the other person is upset about a specific problem, listen carefully and determine the best way to help meet their needs. Avoid being rude or disrespectful in any way.
If you start to get upset, ask the other person for permission to put them on hold for a moment. Take advantage of this time to calm down, breathe deeply, and regain control of the situation

Step 7. Leave concise voice messages
If the person you are calling does not answer, make sure you clearly identify yourself, leave your phone number and give a brief description of why you are calling. Long messages are disrespectful and inefficient, as the person on the other end of the line may stop listening after some time. Use appropriate telephone etiquette when leaving the message and be as concise as possible.
It is good practice to write your voice message before making the call so that you are prepared in the event that the other person does not answer the phone

Step 8. If you take a message, ask for the necessary information
If you are taking a message for someone, it is important to politely ask the other person's name, phone number, and the reason they are calling. Asking about these three things will keep the conversation going and get the other person to proceed as efficiently as possible.