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Q: Telephone Area Codes - # of digits ( Answered 5 out of 5 stars,   4 Comments )
Subject: Telephone Area Codes - # of digits
Category: Computers
Asked by: wayarberry-ga
List Price: $20.00
Posted: 06 May 2002 10:11 PDT
Expires: 13 May 2002 10:11 PDT
Question ID: 13392
I need to build a table that shows telephone area codes and an
indicator that tells whether 7 or 10 digit dialing is required in that
area code (for the entire US).  For example, in Houston, I must dial
ten digits even if
I'm calling my next door neighbor.  This needs to be something I can
obtain routinely (hopefully download from the internet), since area
codes and
7/10 digit dialing requirements are changing all the time.  This needs
to be a very specific answer, not a generality such as "check with
your local telephone company."  Thanks.
Subject: Re: Telephone Area Codes - # of digits
Answered By: joey-ga on 06 May 2002 11:20 PDT
Rated:5 out of 5 stars
As you probably know, the federal agency NANPA (North American
Numbering Plan Administration) metes out area codes for the United
States and keeps track of all routing information regarding area
codes, dialing prefixes, etc.

They provide their information to a company known as Telecordia who
aggregates the information and markets it to customers who need
up-to-date details regarding NANPA's activities, including information
on area codes (NPAs), dialing prefixes, localities, and even time
associated time zones.)
   [more info:]

One such Telecordia report, known as the LERG Report (Local Exchange
Routing Guide) provides many details in an Access database format
about each locality including (but definitely not limited to) the area
codes used and the requirement of 7-digit or 10-digit dialing.
   [more info:]

From the above link, scroll below the detail text and click "Sample
Available".  Download this file and open it.  It is a "self-expanding"
compressed file (meaning it's compressed many files together into one
to save space and to make it easier to transfer.)  When you open it,
it will provide you with several files, one of which is another
self-extracting EXE file.  Open that file and it will produce twenty
or so more files.

Double-click the "LERGDATA.MDB" file (you must have Access installed).
 If it gives you any warning messages, this is because you are running
Access 2000, and it was saved in an Access 97 format.  Just choose to
"open" the file instead of "converting" it.

Once opened, double-click on the table called "LERG6".

In the column marked "LOC NAME" (column 15), you'll see listed the
locality name.  Two columns to the right (column 17, "LOC STATE") is
the state name for each entry.  The column marked "NPA" (column 5) is
the area code for each locality, and the column marked "TD-EO" (column
10) provides the 7/10-digit dialing designation (7 =
"7-digit-dialing", 10 = "10-digit-dialing".)  According to a
Telecordia rep, make sure you look in the TD-EO column, not the TD-AT

Prices for the entire database (not just this sample) are somewhat
steep, and vary depending on your purpose for the data (your industry,
etc.) and the range for the prices is as follows:

    monthly: $13500 - $270000 a year
    quarterly: $4000 - $80000 a year

Now, it's possible that if you need this for educational or
economic-study reasons, etc., they may be able to provide you with the
information cheaper.  Additionally, you may want to check with them to
see if you could get just a subset of the database (e.g. the four or
five columns you need) for a smaller price.

If you would like to contact them about ordering or have any
questions, their contact information is available at:

They can be reached by phone or by email.  I talked to one of their
reps by phone, and she was very helpful.

I hope this works out for you!

wayarberry-ga rated this answer:5 out of 5 stars
Well researched and documented.  I'm impressed.

Subject: Re: Telephone Area Codes - # of digits
From: bsotl-ga on 15 May 2002 20:42 PDT
Since the entire USA allows 1+10 digits even to the same area code,
why not just use 1+10 digits and forget about any rules?
Subject: Re: Telephone Area Codes - # of digits
From: wayarberry-ga on 16 May 2002 07:53 PDT
Are you sure that anywhere in the US you can dial ten digits for local
numbers?  That must have changed very recently because in my recent
trips I have not been able to uniformly dial ten digits.  Thanks.
Subject: Re: Telephone Area Codes - # of digits
From: robertm-ga on 07 Jun 2002 10:34 PDT
Out here, I can't dial the full ten (actually, eleven, including the 1
or 0 before the area code) digits for local numbers; it will tell me I
can't. For example, if my full telephone number is (563) 888-7777, if
I'm calling my neighbor with the number of (563) 888-6666, I'll only
be able to dial the 6 digits. (I remember that seveal years ago, we
would actually just be able to dial just 8 for the prefix and then the
rest of the number, 6666, but we can't anymore.) If I want to call
something not local, like (563) 111-2222, I'll have to dial the full 
1 (563) 111-2222, assuming the person is in my area code. And, of
course, for anything outside, full is required.

PS: All phone numbers are totally made up, except for my 563 area
code. :)
Subject: Re: Telephone Area Codes - # of digits
From: vreiner-ga on 13 Jun 2002 16:42 PDT
Some telephone companies bill differently based on the number of
digits you dial.  So, even if they allow 10-digit dialing to the local
area code, you may be charged for a Zone 3 (Local Toll) or possibly
even a Long Distance charge.

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