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ATLaaS: ATL as a Service

A Thought Leader In Toll-Free Number Management Solutions


In the late 1980s and early 1990s, the North American Numbering Plan Administration (NANPA) implemented calling procedures that required all long-distance calls within an area code to be prefixed with the area code, in order to make it possible to assign central-office prefixes with 0 or 1 in the middle position (except for N11), which would otherwise be wrongly taken by the local telephone switch to constitute the area code.

With area codes dwindling using the existing assignment methods, this grew the number pool for every area code by roughly 25% and furthermore granted the later addition of area codes with middle digits other than 0 or 1.

Requiring a 1 to be dialed before the full number in some areas also accommodated area codes in the form N10, such as 210 in the San Antonio, Texas area and 410 in eastern Maryland. Therefore, an individual calling from San Jose, California to Los Angeles, California before the change would have dialed 213-777-1263 and after the change 1-213-777-1263, which permitted the use of 213 as an exchange prefix in the San Jose area. The preceding 1 also generally indicates a toll call, even though this is inconsistent across the North American Numbering Plan (NANP) because the FCC has left it to the U.S. State Public Utilities Commissions to regulate for traditional landlines, and it has since turned out to be trivial for cell phones and digital VoIP services which currently offer nationwide calling without the extra digit.

The NANP number format is summed up in the format NPA-NXX-XXXX:

ComponentNameNumber Ranges / Notes
NPANumber Plan Area (Area
Allowed ranges: [2 – 9] for the first digit, and [0 – 9] for the
second and third digits. When the second and third digits
of an area code are the same, that code is called an Easily
Recognizable Code (ERC). ERCs designate special services;
e.g., 888 for toll-free service. The NANP is not assigning area
codes with 9 as the second digit.
NXXPrefix (Central Office Code)Allowed ranges: [2 – 9] for the first digit, and [0 – 9] for both
the second and third digits (however, in the geographic area
codes the third digit of the exchange cannot be 1 if the second digit is also 1).
XXXXLine NumberCan be any number from 0 to 9.

For example, 234-235-5678 is a valid telephone number with area code 234, central office prefix (NXX) 235, and line number 5678. The number 234-911-5678 is invalid because the NXX must not be in the form N11. 314-159-2653 is invalid because the NXX must not begin with 1. 123-234-5678 is invalid because the NPA must not begin with 0 or 1.

The country calling code for all countries associated with the NANP is 1. In international format, a NANP number should be listed as +12125550100, where 212 is an area code (New York).

Each three-digit area code can support 7,919,900 telephone numbers:

  • NXX may begin only with the digits 2 through 9, providing a base of 8 million numbers: (8 × 100 × 10000).
  • However, the last two digits of the NXX cannot both be 1, to avoid confusion with the N11 codes.
  • Despite the widespread usage of the NXX 555 for fictional telephone numbers, the only such numbers reserved for fictional use are 555-0100 through 555-0199, with the remaining 555 numbers available for actual assignment as information numbers (subtract 100).
  • In specific area codes, some other NXX prefixes are normally not assigned. These include the home area codes, adjacent domestic area codes, adjacent domestic area code overlays, area codes reserved for future relief efforts, industry testing codes (normally NXX 958 and 959), and special service codes (e.g. NXX 950 and 976).

Some central office codes in certain plan areas are intentionally not issued. For example, numbers 212-718-XXXX, where 212 and 718 are both New York City area codes. These are typically avoided to prevent confusion between an area code and a similarly numbered local exchange in the same region. 958-XXXX and 959-XXXX are usually testing numbers. Using 0 or 1 as the first digit of an area code or seven-digit local number is invalid, as is a 9 as the middle digit of an area code; these are trunk prefixes or reserved for North American Numbering Plan expansion.

Toll-free numbers in the North American Numbering Plan (NANP) are called “800 numbers” after the original area code which was used to dial them. They include the area code 800 (since January 1, 1966), 888 (since March 1, 1996), 877 (since April 4, 1998), 866 (since July 29, 2000), 855 (since October 9, 2010), 844 (since December 7, 2013), and 833 (since April 22, 2017). Area codes reserved for future expansion include 822, 880 through 887, and 889.

North American toll-free numbers are controlled by a network database (SMS/800) in which any toll-free number may be assigned to a local or long-distance telephone number, a T-carrier, or Primary Rate Interface (PRI) line under the control of a Responsible Organization (RespOrg). Direct inward dialing and toll-free number portability are supported.

Additionally, toll-free numbers usually capture the telephone number of the caller for billing purposes through automatic number identification, which is independent of caller ID data and functions even if caller ID is blocked.


In toll-free telephony, a shared-use number is a vanity number (usually a profitable and easily identifiable phone word), which is rented to multiple local businesses in the same competing industry in different cities. In the United States, the RespOrg infrastructure is used to direct calls for the same number to different service providers based on the area code of the calling number.

For instance, a flower company could rent shared use of 1-800-FLOWERS in one city. The number belongs to a company in Carle Place, New York, but is redirected to local flower companies on a city-by-city basis and promoted by being printed on everything from individual bouquets to campaigns against the use of pesticides and their harm to bees.

One previous Mercedes merchant obtained 1-800-MERCEDES, charging other dealers to get calls to that number from their local areas. The automaker unsuccessfully sued MBZ Communications of Owatonna, Minnesota, operated by previous Mercedes merchant Donald Bloom, alleging deception and trademark infringement. Mercedes was ultimately compelled to obtain a different number, 1-800-FOR-MERCEDES.

A company renting 1-800-RED-CROSS at an excellent cost to the individual, local Red Cross chapters as ‘shared use’ was less fortunate. The Federal Communications Commission reassigned 1-800-REDCROSS to the Red Cross as a crisis response number for Hurricane Katrina in 2005.

Shared use can be used as a means to evade FCC regulations against warehousing, hoarding, and brokering toll-free numbers. Technically the number is not being sold, it is being rented one city or area at a time. The practice is potentially dangerous as it leaves local businesses advertising numbers that they don’t own, meaning they have no number portability. The cost incurred per minute and per month is typically far higher for a shared-use number than for a standard toll-free vanity number which a local business controls outright. In addition, there is very little protection if the shared use company fails to meet its obligations or goes out of business.

There are also technical limitations to shared-use vanity numbers. VoIP users are difficult to geolocate as their calls might be gated to the public switched telephone network at a site hundreds or thousands of miles from their actual location. A roaming mobile or internet telephone user is effectively (like the user of a foreign exchange line) attached to a distant rate center a long way from their physical address.


A toll-free vanity number or custom toll-free number is easy to remember. It spells something, means something, or it contains a numeric pattern that is simple to recognize. An easily remembered number is valued as a branding and direct response tool in marketing and advertising for businesses. In the United States, Federal Communications Commission regulations require that numbers be assigned on a first-come, first-served basis.

This gives vanity number proprietors who serve as RespOrgs a commanding advantage in gathering the most valuable phone words, as they have the first pick of newly disconnected numbers and newly introduced toll-free area codes.


There are many benefits for businesses willing to invest in toll-free vanity numbers. From creating strong brand repetition and equity to being able to more accurately calculate ROI in Print Marketing/Advertising, these vanity numbers are well worth their cost to obtain. Whether your marketing budget is in the thousands or the millions, efficiency is key in making your dollars go far. Let’s look at how a toll-free vanity number would be used in specific print marketing/advertising campaigns to provide your business’s Marketing Department with valuable insight on ad performance.

First Step: Assign a unique toll-free number to each individual campaign or ad placement

It’s up to you how granular you get when you first start with direct response tracking, but at the
very least you should have a unique number for each medium you use to advertise. For example,
radio, billboard, television, or print. As you progress you’ll find that each radio spot or each print
advertisement may have very different response rates and tracking them individually will help you
hone which ones have the best return on your investment.

Second Step: Analyze response rates

Once you have assigned numbers to your ads, it’s an easy process to track response rates. Let’s say you assigned number 1 to your print ad in ABC Magazine. There are many call tracking software programs that can help monitor calls and segment them into colorful reports and charts but all you really need, at the most basic level, is the total number of calls. That’s something you can usually get from your regular carrier service.

Third Step: Attribute leads to campaigns

After you analyze your call reports you need to attribute those calls to the corresponding campaign. For example, let’s say number 1 (assigned to ABC Magazine) received 215 unique calls. That means you received 215 responses to your ad in ABC Magazine. Now let’s say you assigned number 2 to your print ad in Industry Magazine. Number 2 received 72 unique calls. Using the total distribution of each magazine, you are able to calculate how well each advertisement performed in relation to the other. It’s really that simple.

Remember the 3 A’s of direct response tracking: Assign, Analyze, Attribute. As you become more experienced with direct response tracking you can track your response in more detail. You can get more granular in your ad tracking. You can even connect call tracking to your Google Analytics. By doing so you will find that your marketing dollars are more impactful, and your ROI increases exponentially as you refine your targets over time. It’s a simple strategy that takes the human element out of lead tracking and eliminates the inaccuracies created with the age-old question “how did you hear about us?

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