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971 Area Code History

In Order No. 99-286, the Commission approved a new area code plan for the 503 area code. It adopted an overlay plan that imposed a new area code over all of the present 503 area code with the exception of the immediate coastal area. The order also established a permissive dialing period, during which telephone numbers could be dialed using either the new or old area code. The new area code was implemented on July 11, 1999. The permissive dialing period (during which both the old and new numbers would work) was extended from that date until January 30, 2000.

What Happened?

On January 19, 1999, Lockheed Martin IMS, the then North American Numbering Plan Administrator (NANPA), presented to the Commission the telecommunications industry's recommendation to introduce a second area code covering the northwest portion of the state of Oregon. Two proposals were presented: a geographic split of the existing 503 area code (the standard legacy solution to area code exhaust), or an overlay of a new area code over the existing 503 area code. The overlay was the recommended solution. The Commission directed its Staff to conduct an investigation to seek the views of the public regarding the date and method of implementation of an area code relief plan for the 503 area code (Order No. 99-105).

The Commission Staff presented its recommendation to the Commission at its April 20, 1999, Public Meeting. The Commission reviewed and approved the recommendations in the Staff Report.


Oregon had already been split into two area codes: 503 and 541 in 1995. The existing 503 area code needed numbering relief because the supply of unassigned prefix numbers (the first three digits of a phone number after the area code) had been sharply limited. The prefix (10,000 numbers) was the minimum assignable quantity at that time. The maximum capacity of an area code is/was 796 prefix codes. There were only about 100 unassigned prefixes in the 503 area code. Under then current growth projections, the available prefixes would exhaust by the end of 1999 or early 2000. At that point, no more prefix codes could be assigned and expansion of telecommunications facilities in the 503 area code would cease. The imminent exhaustion of the available prefixes was attributable to a number of factors, including an influx of new residential and business customers, expansion by existing customers, a high rate of growth in cellular and paging services and the introduction and use of new services, equipment and features.


The following issues were presented during the staff investigation:

  • Whether a "split" or "overlay" method should be used to implement the new area code for the 503 area code in Oregon.

  • If the split method is selected, where would the boundary line between the new area code and the 503 area code be drawn?

  • If the split method is selected, which area would retain the current 503 area code?

  • Would a "technology overlay", in which wireless telecommunications devices receive the new area code, be an appropriate solution?

  • What is the proper time frame for implementation?
The industry proposal

The Telecommunications Industry Group, under the direction of Lockheed Martin NANPA, evaluated eight different area code alternatives. From the eight, the industry selected one split and one overlay as the industry's recommendation. The industry's preferred action was to implement a complete overlay of a new area code over the existing 503 area code. This would require the mandatory dialing of at least ten digits to complete a call. The proposed new overlay would be activated July 11, 1999, with a six-month permissive dialing period to follow, extending the final implementation of the new code to January 30, 2000. During the six-month permissive dialing period, both seven- and ten-digit dialing would complete a call. After January 30, 2000, ten-digit dialing would be mandatory.

The Staff Position

As part of its investigation, Staff sought to inform the public of the issues and receive comments. Staff and the industry informed the public through news releases, bill inserts and newsletters. Staff representatives also met with civic, government and business leaders in several locations throughout the affected area. In addition, public comment hearings were held before an Administrative Law Judge in Gresham, Beaverton, Portland and Oregon City . The Commission also held a Special Public Meeting on April 1, 1999, in Salem to receive further comment from the public and the industry. The Commission received several written comments on the issues.

Staff recommended that the Commission adopt a partial overlay that excluded the coastal area then in area code 503. Staff pointed out that an overlay relieves the necessity for forecasting growth by exchange, and allocates numbers to demand on a regional, not local basis. Under the overlay proposal, Salem would have the same access to numbers as Portland . From a customer perspective, the advantage of the overlay is that no customer has to undergo a number change. All existing numbers stay the same. New numbers are assigned out of the new area code.
The negative results of the overlay are that all local calls require ten digit dialing and the geographic identification of an area code is lost.

Staff believed that it was possible to leave the coastal portion of area code 503 out of the overlay. The rate centers comprising the coastal area of 503 are: Astoria , Bay City, Beaver, Cannon Beach, Cloverdale, Garibaldi, Jewell, Knappa, Nehalem, Pacific City, Rockaway, Seaside , Tillamook and Warrenton. These rate centers (exchanges) had not shown the same growth rate as the remainder of area code 503. They also are not included in the Portland regional extended area service (EAS), and calls between them and the Portland area are toll calls.

Staff noted that the problem facing the Commission in mid 1999 in the 503 area code was very different from that existing in 1995 when the Commission chose to split the state into two geographic area codes, with a new area code covering most of the state outside the northwest region. The traditional franchise service boundaries or territories were no longer well defined because of legal and regulatory changes, including the 1996 Telecommunications Act. The exchange boundaries defining the Portland rate center do not follow county or municipal boundary lines. Setting area code boundaries based on these exchange lines would divide established communities. The complex Portland Metro-EAS arrangements then and now in existence made it impossible to set area code boundaries that do not cross the EAS zones. These arrangements would complicate an area code split solution by requiring a mix of seven- and ten-digit dialing for local calls in the Portland EAS area. For example, a local call from Gresham to Portland would require ten-digit dialing while a local call from Gresham to Beaverton could be accomplished by dialing seven digits. In addition, the various new competing telecommu-nications technologies, which served many customers, were not circumscribed by traditional boundaries and reached many customers far beyond the traditional definitions of exchange areas. In this new market, geographic location was not an essential part of network design. In Staff's view, all of these factors supported the overlay as the better choice.


Split versus overlay

Under the split option, the 503 area code would be divided into two geographic areas, one retaining the current 503 area code and the other receiving a new area code. Under the overlay method, existing customers’ lines would retain the 503 area code while new access lines (telephone, fax, cellular and data) would be given the new area code, regardless of geographic location.

Under the split method, the area receiving the new area code ( Portland under the industry recommendation) would experience the following difficulties:

  • Change of existing telephone number
  • Changing stationary, business cards, catalogs and other materials
  • Reprogramming of telephone numbers in computer systems and cellular phones

The primary disadvantages of the overlay method included the mandatory use of ten-digit dialing for all local calls and loss of geographic identification.

Written and oral comments from the public tended to favor the overlay method over the geographic split. Many of those commenting suggested that the Commission should implement what is called a " technology overlay" under which only alternative telecommunications methods such as cellular phones, pagers and other wireless technologies would receive the new area code. The Commission believed that that method of creating a new area code was not consistent with their policy of making alternative suppliers of telecommunications service available to Oregonians. It might have violated section 253 or other provisions of the 1996 Telecommunications Act. The Act favored the development of competition in the telecommunications industry and removed barriers to entry. Any policy that singled out alternative technologies for providing services for disadvantageous treatment could have been contrary to the Act. The assignation of a new area code just to those carriers and technologies might have been disadvantageous treatment in conflict with the federal law.


The Commission chose to provide the new area code taking into account public and industry opinion, federal law and the Commission's own policies. The Commission adopted the Staff recommendation to approve a partial overlay for implementing the new area code. The overlay would provide consistent ten digit dialing in contrast to the confusing mix of seven and ten digit dialing that would have been necessary under a geographic split. It was also felt that the overlay would make future changes in area codes less frequent and more easily accomplished. For instance, when the 541 area code needs relief, the 971 area code can be an overlay for it also. When it would be necessary to add a new area code to northwest Oregon , an overlay can add a total of 796 prefixes rather than the approximately 400 available to each area code under a split. This process was not viewed to require substantial dislocation and confusion. The Commission acknowledged the problems inherent with an overlay but viewed them to not be insurmountable and would lay the groundwork for future numbering enhancements.

The Commission also adopted Staff's recommendation that the 14 coastal communities now within the 503 area code be excluded from the overlay. They concurred with Staff that nothing would be gained by including that portion of the state in the overlay. They did not extend the overlay to cover it at that time. Thirty prefix codes were reserved for future growth in those communities. An additional 18 prefix codes were reserved for the FCC requirement to allow a 90-day period prior to the implementation of the new area code for future service providers to enter into the 503 area code. Prefixes unclaimed during the 90-day FCC period were reserved for growth in the coastal 503 area. A permissive dialing period was implemented for these areas but was not terminated. Today, one can dial seven or ten digits for a local call in these communities. These communities represent approximately 60,000 telephone numbers.

Numbering situation after the 971 overlay    

After October 1, 2000 all local calls in the 503/971 area code had to be dialed with ten digits and eleven digits for toll calls. Exchanges in Clatsop and Tillamook Counties were excused from this area code overlay and the ten-digit dialing requirement. The overlay was done because the 503 area code was running out of assignable prefixes and at the time of implementation was down to 22 available prefixes. The exhaust dates for Oregon area codes just after the overlay were:

  • 503/971           4th quarter 2015
  • 503/coastal       3rd quarter 2011
  • 541                  4th quarter 2005

Since the overlay and ten-digit dialing were implemented, two events occurred which vastly expanded the number of telephone numbers (addresses) available in Oregon and nationwide. They are number portability (and dialing parity) and thousands block number pooling. Number portability and dialing parity were required by the FCC to implement part of the Telecommu-nications Act of 1996 which mandated that persons changing telecommunications providers could keep their telephone numbers and not be subject to unusual dialing if they did not move out of the exchange area.

Number portability and dialing parity made possible a tenfold increase in assignable telephone numbers. Instead of assigning entire prefixes (10,000 numbers) to telephone switches, the numbers could be assigned in blocks of one thousand telephone numbers. This pushed the exhaust dates for Oregon area codes dramatically. They now are:

  • 503/971           4th quarter 2026
  • 503/coastal       3rd quarter 2011
  • 541                  1st quarter 2008

A technical explanation

In this discussion, the terms rate center, telephone switch and exchange are used almost interchangeably. There are subtle differences between them. A rate center is an anachronism from the days of operator handling of all toll calls and telephone switch handling of local calls. An exchange is a geographic area defined by maps, approved by the Commission, where there are no per unit (toll) charges and having its own telephone switch(es). Initially, all calls between exchanges were toll calls handled by operators. Eventually, calling rose so high that flat rate calling (EAS) was instituted between some exchanges resulting in no toll calling between these exchanges. The area encompassed by these exchanges became known as a rate center for the computation of national long distance charges. That terminology is retained to this day although many toll charges are becoming flat rate since the economies of fiber optic systems have taken away any distance sensitivity to telecommunications costs.

Number availability

There now are 171 prefixes consisting of 61 full prefixes (all 10,000 numbers) and 110 partial prefixes (less than 10,000 numbers) available in the 503 area code spread over 34 rate centers. The number of telephone numbers assigned by telecommunications providers by exchange in an area code is considered confidential and proprietary information by Qwest per their agreement with NANPA. It is, however, available on a non-public basis to the Commission and its Staff.

Before the 1996 Telecommunications Act, numbers were assigned to switches within exchanges in groups of 10,000 (an NXX). This was very inefficient since some switches only serve 200-400 lines. With thousands block number pooling, numbers are assigned to switches 1000 numbers at a time. As stated earlier, this has vastly expanded the amount of telephone numbers available.

Other initiatives, such as statewide EAS, can expand this availability of telephone numbers even more since numbers are assigned by NANPA on a rate center basis and if statewide EAS is implemented, this would result in only one, maybe two rate centers in the state.

The telephone numbering situation in Oregon is much better now than it was when the 971 overlay and ten-digit dialing were instituted.