Phone directories, then and now: how listed numbers became people-search data

The phone book was the first people-search tool most of us ever used. Once a year it landed on every doorstep in town with a line for nearly every household: surname, first name or initial, street address, phone number. Nobody thought of it as a privacy problem, mostly because it was local, it was paper, and finding someone took effort.

The listing itself never really went away. It was copied into databases, merged with other records and put online, and today it sits behind reverse phone lookups and people-search profiles that anyone can query in seconds. This page explains how that happened, what each piece of the chain does, and what you can do about your own number at each step.

The printed directory: listed by default

For most of the twentieth century, a home phone line came with a directory listing unless you asked for something else. The residential white pages printed your name, address and number. The business yellow pages sorted companies by trade.

Some publishers also made reverse directories, sometimes called criss-cross directories. Instead of sorting by name, they sorted by street address and by phone number, so you could start from a number and find the household. These were sold mainly to businesses and kept at many public libraries. In other words, the "reverse phone lookup" is not an internet invention. The internet made it free, instant and national.

Listed, non-listed and non-published

Phone companies have long offered ways to stay out of the book. The terms vary a little by carrier, but the usual split looks like this:

Both options usually carry a monthly charge on a home phone account. Ask your carrier which one you have now. If you have moved or changed providers since you last chose, check again: a new account comes with its own listing choice.

How directory data moved online

Directory data was built to be shared. Under section 222(e) of the federal Communications Act, a local phone company has to provide its listed subscribers' names, addresses and numbers to anyone who asks for the purpose of publishing directories, and the FCC's rules say that includes directories in any format, internet directories among them. Listings marked non-published are not part of that information.

That rule made sense for competing phone books. It also meant that once websites started publishing white pages in the late 1990s, the raw listing data was available to them. From there the next step was short: combine the directory listing with property records, change-of-address data, marketing lists and court records, and a phone number stops being a line in a book and becomes a key that opens a whole profile.

Mobile numbers took a different path. They were never printed in the white pages the way landlines were. When a mobile number shows up on a people-search site, it usually came from somewhere else: a warranty card, an online order, a loyalty program, an app, or a company that shares or sells its customer data. Your phone number now links more of your life than an address ever did, a point my colleague Priya covers in how your phone number links your accounts.

Caller ID name databases

The name that pops up when someone calls you works differently from what most people assume. In the US, the caller's name usually does not travel with the call. When a call arrives, the receiving carrier takes the calling number, looks it up in a caller name database (the industry calls this CNAM), and displays whatever name it finds, usually limited to 15 characters.

There is no single national caller name database. Several companies run their own, carriers subscribe to different ones, and they are not always in sync. That is why an old name, a former spouse's name or a previous owner's name can keep showing up long after a number changes hands.

What you can do here is limited but real:

• Ask your carrier what name it sends for your number, and whether it can be changed to initials or a business name. Some carriers allow this; others do not.
• To hide your number on a single outgoing call in the US, dial *67 before the number. FCC rules require carriers to honor it.
• Some third-party caller ID apps build their name lists partly from the contact lists their users share with them. If one of those apps shows your name to strangers, look for an unlisting page in its help section.

Reverse phone lookup sites

A reverse phone lookup site lets anyone type in a number and get back a name, a city and often an address history and relatives. Most of these pages are front ends for the same profiles you see on people-search sites. The number is just a different door into the same file.

That has a useful consequence: removing your main people-search listing usually takes the reverse lookup page with it. Usually, not always. The PeopleConnect group, for example, says that even after you suppress your report from name searches, your name can still appear in its phone, address or email reports. So after any opt-out, search your own number as well as your name.

A practical routine for each number you use, or used in the last few years:

1. Search the number on the larger reverse lookup and people-search sites.
2. Note which sites show your name with it.
3. Use each site's own opt-out form. Our guide to removing your information from people-search sites has the forms and what each one asks for.
4. Record the dates in a removal log, or in our opt-out checklist.
5. Search the number again in about three months.

Do not pay a lookup site to "hide" a number, and never give one your Social Security number or a copy of an ID to prove the number is yours. A listing removal should be free.

Unlisting with your carrier

Opt-outs clean up copies that already exist. Unlisting reduces new copies. Do both.

1. Check your current status. Ask your carrier, by phone or in your online account, whether your number is listed in the directory and in directory assistance.
2. Choose non-published if you want the stronger option, or non-listed if you only want out of the printed book. Ask about any charge before you agree.
3. Ask about caller ID name. Find out what name the carrier sends and whether you can change it.
4. Check after any change of service. A move, a new plan, a number port or a bundle change can reset your listing status.
5. Know the limit. Unlisting does not recall directories already printed, and it does not pull your number out of broker files that already hold it. That part is the opt-out work above.

If you need a number that strangers can reach, such as for a small business or a classified ad, consider a second number for that purpose so your personal number stays out of new lists.

The National Do Not Call Registry: what it does and does not do

The registry is one of the most misunderstood tools in this area, so it helps to be exact. According to the FTC, the registry is designed to stop sales calls from real companies that follow the law. It is free. You can register at DoNotCall.gov, or by calling 1-888-382-1222 from the phone you want to register. If you register online, you confirm by email within 72 hours.

What to expect, from the FTC's registry questions page:

• Your number shows up on the registry the next day, but it can take up to 31 days for sales calls to stop.
• Your registration never expires. The FTC removes a number only if it is disconnected and reassigned, or if you ask.
• Political calls, charities, debt collectors, purely informational calls and surveys are still allowed, as long as they do not include a sales pitch. So are companies you have recently done business with or given written permission to call.
• The registry does not block calls. It is a list that tells legitimate telemarketers which numbers to leave alone, and scammers ignore it.

If unwanted sales calls keep coming after the first month, report them at DoNotCall.gov. If you lost money or gave out information, report it at ReportFraud.ftc.gov instead.

The registry also has nothing to do with listings. Being on it does not take your number off a people-search site, a reverse lookup page or a caller ID database. Calls and listings are two separate problems, and each needs its own fix.

Your phone number, in one sitting

1. Ask your carrier whether you are listed, and switch to non-published if you want out.
2. Ask what caller ID name it sends for your line.
3. Search your number, and your old numbers, on the larger reverse lookup and people-search sites, and file opt-outs.
4. Register your numbers on the National Do Not Call Registry.
5. Write the dates down and put a recheck three months out.