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Curtis Robinson | The numbering that counts

Published:Sunday | July 3, 2016 | 12:10 AM
Curtis Robinson

As Jamaica prepares for the introduction of an additional area code and 10-digit (instead of 7-digit) dialling for local telephone calls, the Office of Utilities Regulation (OUR) will be running a series of articles to sensitise the public about the process.

THE PUBLIC telecoms network, as we know it today, is a complex unity of diverse systems and fast evolving and converging technologies, with ever-increasing global reach and impact – providing a communication lifeline in practically every sphere of human endeavour.

The transport of voice and data across the network, and the administration of services are controlled and supported by various numbering, naming, and addressing schemes that are essential to the proper identification and addressing of geographic areas, communications networks, network nodes, network functionalities, devices, services, and subscribers.

The numbering resources employed in the various aspects of the network will vary according to technology, services provided, and national telecommunications policies.


There are, at present, 14 different types of telecommunications numbering resources (the most common being the regular telephone number) that are administered by the telecommunications regulatory authorities within what is called the North American Numbering Plan Area.

This is a geographic space comprising the United States and its territories, Canada, The Bahamas, the Dominican Republic, and 16 English-speaking Caribbean countries, including Jamaica.

Not all of the 14 types of numbers are currently employed in Jamaica. Some are subscriber-diallable resources; the others are “visible” only to the telecommunications networks. This article focuses on the regular telephone numbers, with which people are most familiar, and the terms ‘numbering’ and ‘numbers’ will refer to them.


Numbering is a key enabler of telecommunications development and has become an important commercial and competitive factor in the telecommunications industry; it has thus been described as a sine qua non of telecommunications.

It is important, therefore, that the management, assignment, and use of numbering resources be done in a transparent, nondiscriminatory, and efficient manner so as to satisfy current industry needs, promote fair competition, and safeguard supplies to meet future demands.

Individual countries must, therefore, ensure that their National Numbering Plan provides adequate numbering resource capacity and remains adaptable to a highly numbering-dependent environment in which there is increasing flexibility and expanding innovation in technology and service creation, changing customer needs, and a growing dependence on telecommunications.


Section 8 of the Telecommunications Act (the Act), mandates the OUR to:

i) Assign numbers for telecommunications services to carriers and service providers on a non-discriminatory basis.

ii) Develop a plan for the numbering of telecoms services.

iii) Make rules pursuant to that plan regarding the assignment and use of numbers by carriers and service providers.

Accordingly, the Jamaican Natonal Numbering Plan and the Telecommunications Numbering Rules were developed and promulgated by the OUR.

The Jamaican National Numbering Plan is based on the North American Numbering Plan (NANP) which is the basic numbering scheme for the Public Switched Telephone Network for the North American Numbering Plan Area.

The 20 constituent countries of the NANP Area (which share the International Country Code ‘1’) share the NANP numbering resources cooperatively.

The North American Numbering Plan Administration, an agency o f t he Un i t ed States Federal Communication Commission (FCC), holds overall responsibility for the neutral administration of the NANP, subject to directives from regulatory authorities in the participating countries.

In Jamaica, the OUR, as the national numbering administrator, undertakes the primary administrative functions relating to the allocation, assignment and utilisation of all NANP resources and coordinates related activities with the NANPA on behalf of Jamaican Telecommunications Carriers, Service Providers, and users.

The area served by the NANP is divided into smaller Numbering Plan Areas (NPAs), each identified by a three-digit NPA code, commonly called an area code.

The basic NANP number is 10 digits in length, consisting of the three-digit area code followed by a seven-digit local number, in the format:

NXX-NXX-XXXX (where N is any digit from 2 through 9 and X is any digit from 0 through 9)

The NANP number format is thus commonly represented as NPA-NXX-XXXX and the term ‘NXX’ has become synonymous with ‘central office code’.

NPA codes are administered by the NANPA, subject, as noted before, to directives from regulatory authorities in the countries that share the NANP. In each participating country, the relevant regulatory agency has plenary authority over numbers subsumed by the NPAs assigned to that country by the NANPA.


Up until 1995, Caribbean countries that joined the NANP were all assigned numbers exclusively within NPA 809. At that time, just under 12.5 per cent of the numbers had been assigned to Jamaica.

The NPA 809 was added to the NANP in 1958. Thirty-eight years later, in 1995, the exhaustion of the code was imminent owing to rapidly expanding customer bases, changing technologies, and the introduction of various new products and services.

Several Caribbean countries, including Jamaica, were compelled by the circumstances to request their own NPAs from the NANPA.

Jamaica was assigned NPA 876 in June 1996. Activation of NPA 876 took place on Thursday, May 1, 1997. It was envisaged then that the area code would provide sufficient numbering capacity for the next 20 years of demand growth.

However, the country has had to consider the provision of additional numbering resources to augment the existing numbering space after just 13 years.

Now, a new era in numbering is set to begin in Jamaica with the proposed introduction of an additional area code – NPA Relief – and a consequential move to a mandatory 10-digit dialling for all local telephone calls.

NPA Relief activities are undertaken to augment the numbering resources where an NPA is exhausting, and normally involves assigning an additional area code to the area served by the exhausting code.

- Our next article in the series will explore the process of NPA Relief and its implications for the public.

-Curtis Robinson MSc, BSc (Hons), Dip CS, is the manager, technical services (regulation and policy) at the Office of Utilities Regulation. He is a career professional in telecommunication operations and regulation. Email: curtis.robinson@, jm.