Subscriber toll dialling (the historical codes)

Subscriber toll dialling (STD) was introduced in the New Zealand telephone network in the mid-to-late 1970s, a result of the introduction of NEC crossbar-based toll exchanges and their ability to perform number translation. Upper Hutt was the first exchange to implement STD, on 9 April 1976.^[1] One still needed to dial 0 to make a toll call, but instead of calling the operator, one could then dial the STD number directly. Access to the operator was via 010, while other service numbers remained unchanged.

The original STD codes were numbered roughly south to north, with a few exceptions. A complete list of STD codes from 1987 is below:

STD codes were assigned with larger areas having short STD codes (e.g. Auckland - 09), while smaller areas had longer STD codes and shorter local numbers (e.g. Shannon - 06927). The total number length, that is STD code and local number excluding the first 0, usually totalled seven digits, but could vary up to nine, as exchanges often increased the length of local numbers to accommodate new lines.

Reorganisation

With the introduction of NEC stored program control exchanges in the New Zealand telephone network during the 1980s, and the rapid growth in demand, the breakup of the New Zealand Post Office and the creation of Telecom, local telephone numbers were standardised to seven digits. In many parts of the country, the old area code was incorporated into the new number, however in some areas the numbers changed completely.

At the same time, the opportunity was taken to move directory service from 100 to 018 and charge for directory service calls. The justification for doing so was the introduction of a directory service computer system that gave access to current New Zealand telephone number listings, not just those printed in the telephone book, and the need for a separate user pays revenue stream for Telecom Directory Services, which was separate to the 5 regional (local) telephone companies, TNI and Telecom Mobile that Telecom had split itself into, as part of the sale of Telecom and deregulation of New Zealand telecommunications services.

Since 1993, land-line telephone numbers in New Zealand consist of a single-digit area code and a seven-digit local number, of which the first three digits generally specify the exchange and the final four specify the subscriber's unique line at that exchange.

Landlines

New Zealand landline phone numbers have a total of eight digits, excluding the leading 0: a one-digit area code, and a seven-digit phone number (e.g. 09 700 1234), beginning with a digit between 2 and 9 (but excluding 900, 911, and 999 due to misdial guards). There are five regional area codes: 3, 4, 6, 7, and 9. These must be dialled, along with the domestic trunk prefix, when calling a recipient outside the local calling area of which the caller is located. For example, one calling Dunedin from Christchurch must dial 03, even though Christchurch is 03 as well.

The combined domestic trunk prefix^[2] and area codes are:^[3]

• 02 409 for Ross Dependency (Year-round direct dial access to Scott Base & U.S. McMurdo Station - Summer-only access to Zucchelli Station )
• 03 for the entire South Island and the Chatham Islands
• 04 for the Wellington metro area and the Kāpiti Coast District (excluding Ōtaki)
• 06 for Taranaki, Manawatū-Whanganui (excluding Taumarunui and National Park), Hawke's Bay, Gisborne, the Wairarapa and Ōtaki.
• 07 for the Waikato (excluding Tuakau and Pokeno), Taumarunui and National Park and the Bay of Plenty
• 09 for Auckland, Northland, Tuakau and Pokeno.

Mobile phones

Telephone numbers for mobile phones begin with 02, followed by seven to nine digits (usually eight). The first few digits after the 02 indicate the original mobile network that issued the number.

Telephone numbers must always be dialled in full for mobile phones. In the late 1990s however, Telecom mobile phones could dial other Telecom mobile phones without the (then) 025 prefix, making 025 act like a landline area code.

The introduction of mobile number portability on 1 April 2007 meant that an increasing number of mobiles would be operating on a different network from that which originally assigned the number. To find out whether a particular number belongs to a specific network provider, one can text the mobile number of interest to 300. It is a free service provided by 2degrees. A reply will be sent to verify whether the number is operating on their network or not. As of September 2019^[update], this service will work for Vodafone and Spark Active.

Other numbers