The numbering plan explained

What is the Telecommunications Numbering Plan and how does it work?

The New Zealand Telecommunications Numbering Plan is made up of the Number Allocation Rules and the Number Register.

The Number Register includes all the numbers that the NAD administers.  It is broken down into Service Categories and Code Blocks.

Service Categories describe the type of services for which a set of Code Blocks can be used for, for example, the Free Phone Service Category is only used for services that are free to call. A NAD Party must always ensure that the service it is offering with a telephone number fits within the permissable service described in the Service Category for that number.

Code Blocks are a block of telephone numbers within a Service Category that all begin with the same leading digits, such as 09 234. Code Blocks are the smallest unit of telephone numbers that can be allocated to a NAD Party. Code Blocks come in varying sizes. In the Geographic Service Category for example, which is used for typical home phone or "local" services, Code Blocks contain 10,000 telephone numbers which a NAD Party could assign to its customers. For Non-Geographic numbers, which are used mainly for mobile services, a Party could choose whether to activate 100,000 or 1,000,000 numbers within its Code Block.

The Numbering Plan is designed to be flexible enough to enable Parties to innovate and maintain adequate supplies of telephone numbers for their customers without requiring the NAD to make constant changes to the Numbering Plan and adjust New Zealand's numbering supply for new services or rapid growth. Telephone numbers are a finite resource however, and despite popular belief, we can't just make more of them very easily.  Any change requires substantial upheaval, both for the networks that have to carry the new numbers and the customers that have to use them.  Anyone around in the 1980's when local numbers became a standard 7 digit number nationwide will understand what a massive impact a change to the Numbering Plan can have on everyone, everywhere.  The NAD maintains a close watch on numbering supply in New Zealand, to reduce the need to reformat numbers and ensure that every provider has enough numbers to supply their customers and compete in the New Zealand marketplace.

You can view the Number Register, presented specifically for consumers and end users, on our Number Register page.