Toll-free (800, 888, …)
Toll-free services are
essentially automated collect calls. The recipient of the call pays the cost.
However, many toll-free numbers only work within a limited subset of the
North American Numbering Plan countries
(for example, only the U.S.A., or only the U.S. and Canada), so
“replace” codes were implemented for the first three
toll-free codes: 800, 888, and 877.
To dial a U.S.‑only 877 number from another NANP country,
a caller might dial
1-882-nxx-xxxx.
The caller paid the same international call charge as for a standard call
to the United States.
These codes could also be used for calls originating outside the NANP.
However, the use of the 880/881/882 codes was discontinued
as of .
The original toll-free 800 code has been expanded
to 888, 877, 866, 855, 844, and now 833
(as of ).
The next codes added will be 822 and then the remaining 88X codes.
456, 900, 700
International inbound 56K data calls required
a special code because normal international calls may be routed to any North
American carrier at the convenience of the originating country’s telco.
A randomly selected carrier in North America may not provide appropriate
facilities for terminating a high-speed data link. Thus, calls to the 456
area code were routed to a specific carrier based on the number dialed.
This code was not used for domestic calls, but was used for international
calls within the NANP. However, due to declining use of this resource —
primarily because data links over the Internet are easier, faster, and much less
expensive (although less secure) than ISDN data calls — area code 456
was discontinued in 2017.
456 will be available for reassignment as a general-purpose NPA in 2023.
Information services provide some form of content
for a charge over and above the cost of the telephone connection itself.
Many information services provide sexually explicit adult content,
but there are other uses, such as per-incident telephone technical support
for computer software, automated donations to charitable organizations,
psychic / astrological / Tarot readings, stock quotes, and allegedly lucky
lottery numbers.
Carrier-specific numbers may be used for
almost any purpose a long-distance carrier may devise.
There were some carriers in some areas of the U.S. who used 700 as a
replace code for the caller’s own area code, in order to route intra-LATA
toll calls on the long-distance carrier instead of the local “Baby Bell”;
however, that practice is discouraged, since it is now possible to
presubscribe intra-LATA toll calls to your long-distance carrier.
Some carriers use some 700 numbers for information services at
charges comparable to 900 numbers.
Other carriers use 700 numbers for purposes carrying more modest price tags.
Almost all carriers use
1-700-555-4141
to verify the caller’s default
long-distance carrier for inter-LATA calls. Many areas use
1-NPA-700-4141
to verify the intra-LATA toll carrier, where “NPA” is the caller’s
own area code; however, you should check with your telephone company, since
700-4141
may also be an ordinary number in your area code.
500, PCS, and iPads
Non-geographic Services:
Originally, area code 500 was intended to be used for
“Personal Communications Services”
(a.k.a. “the Other PCS”), which in this context refers not to
cellular telephones, but rather to so-called “follow-me” numbers.
The idea was to have a single number, say
(500) 123-4567,
that you could program to ring your home phone from 6 to 10 p.m.,
go directly to voicemail at night, and ring your desk at work during the day.
The number could also have some sort of response menu, along the lines of
“press 1 for voicemail, 2 for fax, 3 for cellphone.” Some
implementations also allowed the same 500 number to be used for caller-pays or
called-party-pays: dialing
1-500-xxx-xxxx,
the caller would pay the cost of the call, but dialing
0-500-xxx-xxxx,
the caller could enter a 4-digit PIN to charge the call to
the owner of the number. However, in spite of efforts to keep
telesleaze
out of the 500 number space, some unscrupulous operators
exploited a feature that allowed 500 numbers to forward
internationally, with the additional charge borne by the
caller with only a “press 1 to accept” warning,
if that.
“Follow-me” numbers never really
caught on, so the numbering space (including expansion codes
521, 522, 523, 524, 525, 526, 527, 528, 533, 544, 566, 577, and 588)
is now used primarily for purposes that require a telephone number but
that do not require a number associated with a specific geographic location.
In fact, most of these numbers are not dialable
on the public telephone network.
One example is devices such as iPads equipped to use a cellular data network.
For billing purposes, there needs to be a unique number associated with the
iPad, even though that number cannot be used for inbound calls to the device.
Home alarm systems that connect to a wireless carrier would also qualify.
There are also other devices that may not use the phone network at all,
but for some reason need a non-geographic telephone number as an address.
Area codes 511, 555, and 599 are reserved, so, now that the 522 code
has filled up, miscellaneous unused
5XX codes will be used,
beginning with 521 and 523 through 529, and then unused 53X codes.
Area code 529 went into effect
;
area code 532 will go into effect some time in early to mid-2023,
followed by 535, probably in late 2023 or early 2024, and 538,
a few months after that. The other codes reserved for this purpose are
538, 542, 543, 545, 546, 547, 549, 550, 552, 553, 554, 556, 558, 569, 578, and 589.
