Wholesale: Products & Services

Directory Assistance List (DAL) - V19.0

History Log

Product Description

Directory Assistance List (DAL) information consists of name, address, and telephone number for end-users of CenturyLink™, other Local Exchange Carriers (LECs), Competitive Local Exchange Carriers (CLECs), and Resellers and other service providers that provide listing information to CenturyLink. You receive the same information CenturyLink uses to provide DA services. You may use DAL information for providing DA Services and for other lawful purposes according to the terms and conditions of your DAL Agreement with CenturyLink. DAL information may not be used for purposes of directory publishing. DAL telephone number information for end-users with nonpublished service will only include the local Numbering Plan Area (NPA), address, and a nonpublished status indicator. The nonpublished telephone number will not be provided, however, you will be given access to CenturyLink's Non-Pub Bureau. The Non-Pub Bureau is available in the event an urgent message needs to be relayed to a subscriber with nonpublished service. Click here for additional information regarding the Non-Pub Bureau.

DAL information identifies end-users as residential, business, or government subscribers.

There are three primary features of DAL:

  • Initial Database Load List - you are supplied with initial DAL database load file(s). This list includes all listings in the CenturyLink DA database.
  • Daily Update List - after the initial database load file(s) have been provided, CenturyLink supplies you with files containing all daily update activity including new services, changes, and disconnects.
  • Database Reload - in the event that a reload of listings from CenturyLink's DA database is required to validate, synchronize, or reconcile your database, a reload is available according to the terms identified in your DAL Agreement.

DAL information is offered as follows:

  • To CLECs and Resellers (or their agents) - according to the terms and conditions of a DAL Agreement with CenturyLink.
  • To Interexchange Carriers (or their agents) - according to the terms and conditions of a DAL Agreement with CenturyLink.
  • To Independent DA Providers (or their agents) who qualify under 47 U.S.C. � 251(b)(3) - according to the terms and conditions of a DAL Agreement with CenturyLink.


DAL is available throughout the United States.

Terms and Conditions

A contract with CenturyLink allows you to use DAL information according to one of the following options:

  1. To build and update a database for delivery of DA services that addresses specific end-user requests to your DA/Operator Services (OS) operators or responds to electronic queries to your DA database for information.
  2. To respond to voice or electronic DA queries and any other lawful use of DAL information for business purposes. Listings marked as nonpublished, nonlisted, or "omit from lists" shall not be used for marketing purposes except as specified in your DAL Agreement.

CenturyLink will make commercially reasonable efforts to ensure that all listings, included in the DAL information, belonging to its retail end-users are accurate and complete. All other providers' DAL information is provided "as is, with all faults". CenturyLink will also review all its listings for end-user requested restrictions on use and will identify the restrictions to you.

You are responsible for the following:

  • Daily updates of DAL information should be obtained and entered into your DA database in a timely manner
  • Implementation of quality assurance procedures that test DAL information for accuracy
  • Identification of yourself, by company name or operating company number, to your end-users
  • You must take reasonable measures to prevent disclosure and unauthorized use of CenturyLink DAL information including adequate computer security.
  • Conducting audits regarding your use of DAL information upon request from CenturyLink. You may also request the same type of audit from CenturyLink.

Technical Publications

No specific CenturyLink Technical Publications are associated with DAL.


Rate Structure

Recurring charges are related to the following:

  • Daily Updates - daily change activity affecting DAL information in the listings database.
  • Output Media - delivery of electronically transmitted file(s)

Nonrecurring charges are related to the following:

  • Initial Database Load - a snapshot of the data in the CenturyLink DA database or portion thereof at the time the order is received.
  • Reload - a snapshot of the data in the CenturyLink DA database or portion thereof required to refresh the data in your database.
  • One-Time Set-Up Activities - special database loads.
  • Output Media - delivery of electronically transmitted file(s)


Rates for Interexchange Carriers, Independent DA Providers, CLECs and Resellers, and all other entities purchasing listing information are in accordance with their DAL Agreement with CenturyLink.

Tariffs, Regulations and Policies

The Tariffs, Regulations and Policies section does not apply to DAL.

Optional Features

You may order the initial DAL information load or update files for CenturyLink QC or, where technically feasible, you may order the initial DAL information load or update files using Full Region, Geographic Areas, Area Code and Prefix, Residence Only, and Business Only. For more information, you may contact the DAL Account Manager.


Features Benefits
Over 15 million CenturyLink, LEC, and other CLEC listings Build a database to provide DA and OS using the same quality data used by CenturyLink operators.
Listing updates Daily updates to your listing database will keep it current and accurate.
Database reload Will refresh, repair, or re-synchronize your database.
Flexible ordering options Order based on individual business need(s) to support various offerings.
Easy to use file format Available in Activity Listing Interface Contract (ALIC), Telcordia developed, file format.
Flexible media delivery options Files can be sent using File Transfer Protocol (FTP), File Transfer Protocol Secure (FTPS) or Network Data Mover (NDM)


Applications of DAL that may be valuable to your organization include the following:

  • You will have the ability to create and maintain a listing database that can be used to provide local, regional, and national DA and OS.
  • You can add the DAL information from CenturyLink to your current DA database to improve your level of service.
  • You can use DAL information for other lawful purposes according to the terms and conditions of your contract with CenturyLink.


Product Prerequisites

If you are a new CLEC and are ready to do business with CenturyLink, view Getting Started as a Facility-Based CLEC or Getting Started as a Reseller. If you are an existing CLEC wishing to amend your Interconnection Agreement or Customer Questionnaire, additional information is located in the Interconnection Agreement.

All other DA Providers should contact the CenturyLink DAL Account Manager.


General pre-ordering information is located in the Pre-Ordering Overview.

Requests for DAL information require 30 business days to complete. You must have the transmission network in place and tested prior to the due date. If the transmission network is not in place and tested by the due date, you must renegotiate the due date.

For information regarding record layouts and formats for DAL files, reference the DAL User Guide.

If you need a current list of all of the NPAs/NXXs in the CenturyLink DA database, contact the CenturyLink DAL Account Manager.


General ordering activities are identified in the Ordering Overview.

Contact the DAL Account Manager to obtain copies of the current standard contract and technical specifications.

The DAL Account Manager will perform the following:

  • Review your contract and technical specifications with you prior to ordering DAL information service
  • Establish your billing account
  • Arrange for test files to be delivered to you
  • Facilitate all meetings with CenturyLink technical teams to discuss testing network links and file transfer processes
  • Supply all technical documentation required to use DAL information

If you need Zenith/Enterprise/Commerce Numbers and the related telephone numbers operators must dial, contact the CenturyLink DAL Account Manager.

Provisioning and Installation

Provisioning activity does not apply to this product.

Maintenance and Repair

If you encounter an error with any of the listings you receive, a discrepancy form should be e-mailed to Listings Escalations, click here to obtain the e-mail address Click here to download the Listing Discrepancy Form.

Contact the CenturyLink DAL Account Manager if you encounter any difficulties with the discrepancy form or need additional information.


Recurring charges for daily update file(s) are billed on a listing transaction basis. A transaction refers to the time, occurrence, and type of change in a subscriber listing. For example, a change in a subscriber telephone number will generate two transactions. The first transaction will remove the listing record with "Out" type of activity. The second transaction will be an "In" type of activity to input the new listing record. In the case of listing caption changes, the entire caption set is replaced in the file so that you know the proper placement within the caption set. All caption records are transmitted in the daily update file, however, only those with a change constitute a billable transaction. Click here for more information regarding billable transaction types. Charges for transmitting daily update files are also billed on a recurring basis. For more detailed information regarding billable transactions and sample billing, contact the CenturyLink DAL Account Manager.

Nonrecurring charges are billed by the 15th of each month for activity related to initial file load(s), file reload(s), one-time event(s), and associated transmission(s) during the previous month. A summary statement will be included with each bill that provides listing counts and associated charges.

The CenturyLink Local Exchange Invoicing System (LEXCIS) provides billing for DAL information. For billing information, you may contact the LEXCIS Billing Service Representative - see Contacts below.


Local CenturyLink 101 "Doing Business With CenturyLink"

  • This introductory web-based training course is designed to teach the Local CLEC and Local Reseller how to do business with CenturyLink. It will provide a general overview of products and services, CenturyLink billing and support systems, processes for submitting service requests, reports, and web resource access information. Click here for Course detail and registration information.

The Product Description, Pre-Ordering, and Maintenance sections of this document contain specific information for DAL.

For additional information contact the DAL Account Manager.

View additional CenturyLink courses in the Course Catalog.


CenturyLink contact information is available in the Wholesale Customer Contacts.

Frequently Asked Questions (FAQs)

1. How many listings are there in each NPA?
Contact the DAL Account Manager for the most current number of listings in each NPA.

2. Does CenturyLink provide the listings of other CLECs in its database when it provides its own?

3. Are there independent telephone companies in CenturyLink QC's territory that do not provide listings to CenturyLink?

4. Will all caption set updates be full caption replacements?

5. Does CenturyLink use government branch indicators for local, state or federal branches of government?
Yes, the branches CenturyLink uses are federal, state, county, city, tribal, and regional.

6. Does CenturyLink provide the full 10-digit number on all listings?
No. Nonpublished listings will only contain the NPA. The other 7 positions in the field will be blank.

7. Will Nonpublished listings have a special indicator to distinguish them from other listed records?

8. If fields allow for data to be abbreviated, will CenturyLink provide a table of the abbreviations?

9. Does CenturyLink provide the option for a DA Provider to order either part(s) of the database or the entire database?
Yes, DAL may be ordered by Full Region, Geographic Areas, Area Code and Prefix, Residence Only, and Business Only.

10. Can DA Providers order just the business listings?
Yes. Business listings (including government) can be ordered separately.

11. How will CenturyLink handle an NPA split?
You will be notified of NPA splits in advance of receiving the NPA reload of the effected records.

12. How does CenturyLink provide initial load and update files?
FTP, FTPS, and NDM are the only methods used by CenturyLink to deliver files.

13. Does CenturyLink have the capability to provide DAL updates for all CenturyLink QC states on a single file from a single site?
Yes, CenturyLink can concatenate the files from its 3 regional databases into one file and send it from one location, but does not recommend it. If service order processing is delayed in one region, it delays the delivery of data for all regions.

14. How often will CenturyLink send updates? If less than 7 days, on which days of the week will CenturyLink send the files?
Monday through Friday unless a holiday falls during that period or special processing is necessary. Monday's file contains updates for Saturday and any special processing done on a Sunday.

Last Update: July 17, 2015