How to Put an End to Unwanted or Harassing Phone Calls

Posted: Oct 01 1992  | Revised: Jun 01 2016


This is for informational purposes only. We are not able to counsel stalking victims.

  1. What makes a phone call harassing?
  2. How often do I have to get these calls to make it harassment?
  3. Who should I contact when I get harassing calls?
  4. What can my local phone company do if I am receiving harassing calls?
  5. Is the phone company always able to solve harassing phone call problems?
  6. What can I do to stop harassing calls without going to the phone company or police?
  7. What is the "pressure valve" strategy?
  8. What precautions can I take to prevent harassment?
  9. How can I stop telemarketing calls?
  10. Sometimes my phone rings and there is no one on the line. What is happening?
  11. What can I do to stop other kinds of unwanted calls?
  12. Can I use Caller ID to stop unwanted calls?
  13. What does Privacy Manager do?

1. Introduction

Obscene or harassing phone calls can be one of the most stressful and frightening invasions of privacy a person experiences. And unwanted phone calls, while a minor problem when compared with threatening calls, can still be a major inconvenience. Fortunately, there are steps you can take to help put an end to these unwelcome intrusions.


2. What makes a phone call harassing?

When someone calls and uses obscene or threatening language, or even heavy breathing or silence to intimidate you, you are receiving a harassing call. It is against the law in California and other states to make obscene or threatening calls. (California Penal Code section 653m, Penal Code section 422-422.1)


3. How often do I have to get these calls to make it harassment?

Just one unwelcome call can be harassing; but usually your local phone company will not take action unless the calls are frequent. However, if a call specifically threatens you or your family with bodily harm, the phone company will generally take immediate action.


4. Who should I contact when I get harassing calls?

Local phone companies have varying policies on whether to call the phone company or the police first. Some recommend that you first call the phone company's business office and explain the problem. A representative will connect you with the "annoyance desk." Other phone companies may require you to file a formal complaint with local law enforcement before they will deal with the matter. To find out what your phone company's policy is, contact the business office and ask for assistance.  AT&T policies are available online at their Annoyance Call Bureau site.  Click on "Annoyance Call Types" for specific guidance.  Verizon policies are available at their Unlawful Call Assistance page.


For serious threats, if life or property are threatened, or if calls are obscene, you should call the police and file a report. Provide as much information to law enforcement as you can. Indicate the gender of the caller and describe the caller's voice. Note the time and date of the call(s). What did the caller say? How old did he/she sound? Did the caller seem intoxicated? Did he/she have an accent or speech impediment? Was there any background noise? Was a phone number/name displayed on the Caller ID device?


5. What can my local phone company do if I am receiving harassing calls?

If the calls are frequent or particularly threatening, the phone company can set up a "Trap" on your phone line. The Trap allows the phone company to determine the telephone number from which the harassing calls originate. You must keep a log noting the time and date the harassing calls are received. Traps are usually set up for no more than two weeks. The phone company does not charge a fee for Traps.


A phone company service called Call Trace may also be able to help track down harassing calls. Immediately after receiving a harassing call, you enter the code *57 on your phone and the call is automatically traced. Call Trace is easier than using a Trap since the customer does not have to keep a phone log. But Call Trace technology works only within the local service area. (Look in the "Customer Guide" section of the phone book or the phone company's web site for a description of your local service area.)


Call Trace must be set up in advance by the individual receiving harassing calls, and it requires a fee for use. However, in situations where the phone company would ordinarily use a Trap, you might not be charged if the phone company suggests that Call Trace be used as an alternative. Be sure to ask.


The information collected from Call Trace or from a Trap is turned over to law enforcement personnel, not the customer. Law enforcement officers try to stop the harassing calls by either warning or arresting the harasser. With both Call Trace and a Trap, your phone conversations are not listened to or recorded by the phone company.


6. Is the phone company always able to solve harassing phone call problems?

No. If the caller uses a phone booth or multiple phone lines, the phone company and law enforcement officials may never get enough identification to take further action. In cases like these, changing your phone number might help. Also, you might want to get an unlisted or unpublished number. In addition, the tips listed below for discouraging other types of unwanted calls may be of help.


7. What can I do to stop harassing calls without going to the phone company or police?

First, simply hang up on the caller. Do not engage in conversation. Typical crank callers are seeking attention. You have "made their day" if you say something to them or express shock or anger.


If the silent treatment does not work, you might try putting a message like this on your voice mail system:

I'm sorry I/we can't come to the phone right now but you must leave a message. I/we are receiving annoyance calls and the phone company has a trap on this line. If you do not leave a message I/we will assume that you are the annoyance caller and this call will be traced.


If you answer the phone and the harassing caller is on the line, another suggestion is to say: "Operator, this is the call." Then hang up. Or say the word "trap," what time it is and the date; then hang up.


8. What is the "pressure valve" strategy?

Some threatening calls are part of a larger pattern of abuse, such as stalking. Some experts recommend in these situations to get a new phone number, but keep the phone number being called by the harasser and attach a voice mail machine or message service to that line. Turn the phone's ringer off and don't use that phone line for anything other than capturing the calls of the harasser.


This is the pressure valve strategy. The harasser will continue to call the unused number and will think that he/she is getting through. Instead, you are simply using the number to gather evidence. You will want to save tape recordings of the calls.Get another phone number for your use, and be sure it's unlisted and unpublished. Give the number to trusted friends and relatives only. Do not give it to your bank, credit card company or credit bureau. Put passwords on all of your phone accounts (local, long distance, and mobile). Tell the phone companies in writing that they must not disclose any account information to anyone but yourself, and only when the correct password is given.


9. What precautions can I take to prevent harassment?

Do not disclose personal information when called by someone you do not know. They might be checking out the residence for possible robbery or other crime. If the caller asks what number they have called, do not give it. Instead, ask them to tell you what number they dialed.


Children should be instructed to never reveal information to unknown callers. Instead, they should be taught to record the caller's name and phone number along with date and time.


Do not include your telephone number on the outgoing message of your voice mail service if you wish to keep your number private. By omitting your phone number from your message, you prevent random dialers and people with Call Return (explained below) from capturing this information.


10. How can I stop telemarketing calls?

The most effective and easiest way to prevent telemarketing calls is to register your home and personal phone number(s) with the National Do Not Call Registry operated by the Federal Trade Commission (FTC).

You can sign up for the Do Not Call Registry two ways:

  • The FTC's toll-free phone number is 888-382-1222 (TTY: 866-290-4236)
  • Online registration is available at the FTC's web site,

11. Sometimes my phone rings and there is no one on the line. What is happening?

Random digit dialing devices are able to determine all possible phone number combinations, even unlisted numbers, and dial them much more rapidly than any person can. Some telemarketers use "predictive dialing" technology to call consumers who are not on the National Do Not Call Registry. A computer dials many phone numbers in a short period of time. When an individual answers, the computer seeks a sales representative who is not occupied and connects the call. If all employees are handling other calls, the consumer hears dead silence. These are "abandoned calls."


Many people are frightened when they receive abandoned calls. They wonder if someone is harassing them, or if a burglar is checking to see if they are not home. In most cases, these calls are from telemarketers.


Prior express written consent is required for all autodialed or prerecorded calls or text (SMS) messages made to cell phones or residential landlines for marketing purposes.   


The FTC has a Consumer Alert on "robocalls" at and an infographic at


If you are receiving many abandoned calls a day, you can call the annoyance department of your local phone company and ask that a Trap be placed on your line. In extreme situations, the phone company might be willing to contact the offending telemarketer and request that your phone number be place on its "do not call" list. If the repeated calls are from a malicious individual who is harassing you rather than a telemarketer, the phone company will report the number to law enforcement as described in the beginning of this guide.


California Public Utilities Code 2875.5 requires telemarketers to limit abandoned calls to fewer than 1% of their total call volume. 


12. What can I do to stop other kinds of unwanted calls?

Sometimes calls are annoying but are not serious enough to involve law enforcement as is necessary with either a Trap or Call Trace. These might include telemarketing sales calls, wrong numbers, overly aggressive bill collectors, and prank calls. There are several steps you can take to discourage such unwanted calls.


An answering machine or a voice mail service is one of the best ways to limit unwanted calls. An answering machine records messages when you are not available and can also be used to screen your calls. Similar to an answering machine, a voice mail service or an answering service can also discourage unwanted calls.


Another product on the market is an attachment to the telephone called an "inbound call blocker." It allows only those callers who enter a special numeric code onto their touchtone phone pad to ring through to your number. This device is highly effective in preventing unwanted calls. However, you must be certain to give the code to everyone you want to talk to. Even so, you could miss important calls from unexpected sources, like emergency services.


In most areas of the country, Custom Calling services are available from the local phone company which can help limit unwelcome calls. However, before you sign up, look carefully at the services to be certain they will work in your situation and are worth the monthly fee. Also remember that many of these features only work within your local service area. Calls coming from outside the area might not be affected by these features. (Consult the "Customer Guide" section of the phone book or the company's web site to find out the boundaries of your local service area.) Keep in mind, these services require a fee, either month-to-month or per-use. To avoid having to pay for call screening on an ongoing basis, consider purchasing a device that attaches to the telephone, such as the call screening devices mentioned above.

  • Call Screen (*60): Your phone can be programmed to reject calls from selected numbers with a service called Call Screen (some phone companies might use a different name). Instead of ringing on your line, these calls are routed to a recording that tells the caller you will not take the call. With Call Screen, you can also program your telephone to reject calls from the number of the last person who called. This allows you to block calls even if you do not know the phone number. Most phone companies charge a monthly fee for this service.

Call Screen is not a foolproof way to stop unwelcome calls. A determined caller can move to a different phone number to bypass the block. Also, Call Screen does not work on long distance calls from outside your service area.

  • Priority Ringing: You can assign a special ring to calls from up to 10 numbers - the calls you are most likely to want to answer. The rest can be routed to voice mail. There are ways callers can get around Priority Ringing when it is used as a screening tool. The harasser can switch phone lines and avoid the distinctive ring.
  • Call Return (*69): This service allows you to call back the number of the last person who called, even if you are unable to answer the phone. Some people suggest that Call Return can be used to stop harassing callers by allowing you to call the harasser back without knowing the phone number. Use caution with this method of discouraging harassing callers, however, as it could actually aggravate the problem. This service is paid on a per-use basis.

13. Can I use Caller ID to stop unwanted calls?

With Caller ID, customers who pay a monthly fee and purchase a display device can see the number and name of the person calling before picking up the phone. Some people believe Caller ID will help reduce harassing or unwelcome calls. Others, however, raise privacy concerns about the technology since subscribers to the service can capture callers' phone numbers without their consent.


To help consumers protect the privacy of their phone numbers, state public utilities regulators (for example, the California Public Utilities Commission) require local phone companies to offer number blocking options to their customers.


There are two blocking options to choose from. If the customer chooses Per Line Blocking (called Complete Blocking in California), their phone number will automatically be blocked for each call made from that number. If the customer chooses Per Call Blocking (called Selective Blocking in California), the phone number is sent to the party being called unless *67 is entered before the number is dialed. When the number is blocked by either of these methods, the Caller ID subscriber sees the word "private" or "anonymous" on the Caller ID display device.


Because of these blocking options, Caller ID is not likely to allow you to capture the phone number of the determined harasser. Most harassers will block their phone numbers or will call from payphones. However, Caller ID can be used by people receiving harassing calls to decide whether to answer. They can choose not to pick up calls marked "private" or numbers they don't recognize.


A companion service to Caller ID, called Anonymous Call Rejection (ACR), requires an incoming call from a blocked number to be unblocked before the call will ring through. Use of this feature forces the harasser to disclose the number - by entering *82 - or to choose to not complete the call. But a determined harasser can get around this feature by using a payphone. This service can be added to a consumer's local phone service for a fee or at no charge depending on the carrier. It is activated and deactivated with the touchtone code *77.


14. What does Privacy Manager do?

Most local phone companies offer a service called Privacy Manager. It works with Caller ID to identify incoming calls that have no telephone numbers. Calls identified as "anonymous," unavailable," out of area" or "private" must identify themselves in order to complete the call. Before your phone rings, a recorded message instructs the caller to unblock the call, enter a code number (like the inbound call blocking devices mentioned above), or record their name. When your phone rings, you can choose to accept or reject the call, send it to voice mail, or send a special message to telemarketers instructing them to put you on their "do not call" list.