Building and maintaining friendships requires a number of important skills. One that is frequently overlooked has to do with telephone etiquette. By making mistakes in this area, you could be inadvertently upsetting existing friends and scaring off new ones. Here are the five worst offenses:

1. Forgetting to “delete” the call

When a friend answers the phone in response to your call, remember to identify yourself first and ask about their hours. Callers often approach their own agenda, not thinking that they might be disturbing their friends.

Example: “Hi Bill, this is Ron. I just called to chat and catch up. Is this a good time to talk?”

Be sure to identify yourself because some people aren’t good at recognizing voices, especially if you’ve just met, and may feel uncomfortable having to guess. More problematic, when you don’t ask if your friends can talk, you put them in the awkward position of having to interrupt them and explain that they can’t stay on the phone.

2. Call waiting abusive

No one likes to feel discounted, but call waiting users often make people feel that way. When friends of an acquaintance of mine ask him to wait for call waiting, he replies: “Hey, what am I, chopped liver?”. I agree. I think if you contacted me by phone, you got there first and I owe you a full call.

If you think you should use call waiting, do two things. First, limit the number of interruptions. I know people put their phone down three or four times during a conversation to check for incoming calls. As I sit twiddling my thumbs, I fight the urge to hang up in disgust.

Second, let the person already on the line know that you’re expecting an important call and you’ll have to interrupt it when it comes in. That way your friend will be warned and hopefully won’t feel dismissed.

Some people use call waiting for valid reasons. A relative may have health problems or an ongoing crisis may demand her immediate availability. They may be waiting for a guest who will call with arrival times or directions.

I suspect that other people obsessively respond to the call waiting beep for fear of missing something. I sometimes joke with a friend who can’t ignore the beep: “You’d better hurry, you don’t want to miss that $200 million from Publisher’s Clearing House!”

3. Talk non-stop

Some people have difficulty ending a phone call. We are often afraid to hear from them, especially when we have things to do. Every once in a while I talk to acquaintances who just don’t know how to put a period at the end of a sentence. They connect each statement to the next with the word “and,” carefully avoiding an equal exchange. The answering machine filtering option was invented for such people.

Usually, marathon talkers ignore hang up signals. When we try to end the conversation, they often ignore our efforts and don’t recognize the generally accepted signals people use when they want to get off the phone. Here are a couple of examples:

“Okay then, Karen. I’m very glad you called. It has been a pleasure hearing it from you.”

“Well Steve, this was fun! Let’s talk again soon.”

Look at the sentences in bold. Using the past tense is the most common way to let others know that you want to end a call.

I feel trapped every time someone ignores the signals and continues to tackle new topics. It’s a tough dilemma because I don’t want to be rude, but I do want to get off the phone.

People are marathon talkers for a number of reasons, including feeling lonely or bored, wanting to vent or gossip, or needing an audience to entertain. Whatever the reason, unsurprisingly, they leave numerous voicemail messages for people who are mysteriously almost always out of the house.

4. Multitasking

Many people pride themselves on their ability to do extra “productive” things while on the phone. Some can make it and their phone partners don’t notice their divided approach, but most can’t.

These are the giveaways: They don’t always track talking points properly, have an intermittent vague or distant tone of voice, and make noise doing whatever it is they’re doing. I heard paper ripping (checking your mail), running water (washing the dishes), babies crying (changing diapers or feeding them), and, I kid you not, the sound of clinking (sitting on the pot).

Most of us prefer to chat with people who can give us their full attention.

5. Misuse of voice mail

Voicemail is certainly a great convenience, but many people unknowingly annoy their friends by abusing it. Here are some guidelines:

As with person-to-person calls, always start your message by identifying yourself and then keep it brief. Most people don’t want to listen to long, buzzing messages. They want a fast one that they can write and perform.

Also, do your best to structure your message to avoid unnecessary callbacks. For example, if you want to reschedule an appointment, say the following: “Kathy, I’d like to reschedule our appointment from 7:00 to 7:30. If that’s okay, don’t call back. Otherwise, call me at 555 -4343 and we’ll figure something out.”

Leave your phone number each time (not everyone has it memorized) and say it slowly. Be sure to leave the correct number if you are somewhere other than home and do not have your cell phone.

Since most people already know how voicemail works, use a short greeting. I once returned a call to a customer whose greeting consisted of her five-year-old son snapping her fingers and humming the entire theme song from the Partridge Family TV show, twice. He was stuck in phone hell.

For years, my Uncle Tony offered me a short, reassuring message: “You know what to do. Do it.”

My favorite of all time though is a phone message from a musician friend. He wins the prize promptly when he says, “Your solo!”