1.Don’t phone before 7:00 am and after 9:00 pm [unless in an emergency or an important overseas call]. Also avoid calling people during mealtimes. People don't expect you to drop in and visit at these times, unless it is arranged. This includes texting, though you would obviously not text for emergencies.
2.Ensure the number you have is correct. If you do disturb someone and it’s the wrong number then ‘please’ have the decency to say, “I’m so sorry! I have the wrong number!” That individual may be ill, in a wheelchair, or elderly, etc, so you should show respect and apologize for their inconvience

3.When someone answers the phone don’t be harsh and abrupt by telling them what you want first. This confuses them and makes them wonder who you are. You also appear very rude, which is bad if you need a favour from them. It gives the wrong impression before you start! And don’t say, “Who is this?” You phoned them, so introduce yourself and state who you are and what you want – politely! For example; say “Hello, my name is Mrs. Peppermint, I'd like to speak to Mrs. Sally Lemon. Is she available?” Or if you are making inquiries, state; “Hello, this is Mrs. Peppermint. I saw an advert in the local paper for a shop assistant; is that position still open?” When finished, say, “Thank you for your help. Goodbye” and be genuine! Now ensure you give them time to say ‘Goodbye’ too!!
4.Give people a chance to answer their phone! They could be outside in their garden, knitting, baking, washing the car or at another end of the house. Don’t just ring three times and hang up! It's annoying when you stopped doing something, go into the lounge to answer and just as it gets to your ear the caller hangs up
5.If you must carry on two conversations at once you should always excuse yourself from one and resume it later. Say, "I'm sorry, can you hold on a minute; my boss is telling me something", and wait for the person's answer. If the personal conversation will last more than a minute, it would be better to ask, "Can I call you back? My mother needs to talk to me and it may take a few minutes"
6.When on the phone, don't talk with others in the room. What's worse than having a phone conversation with one who chats, perhaps not listening to what you're saying, and you can't tell if they are speaking to you or others.
7.Avoid using the computer while on the phone unless it's part of customer services. It is extremely rude and unpleasant when someone makes you listen to a clacking keyboard
8.Improve your manners when speaking. Here are other common etiquette mistakes and their solutions:
Never say "Yeah". It's "Yes" or preferably "Yes, please".
It's never "Huh?" or "What?", it's "Pardon?"
Instead of "Nah", say "No, thank you."
Always use "May I...?" instead of "Can I?"