The National Provincial Championship would include professional and semi-professional players, and consist of the top fourteen financial and sporting best performing regional teams.

Eight other teams have won titles from both periods: Wellington (6), Waikato (3), Otago (2), Taranaki (2), Tasman (2), Bay of Plenty (1), Counties Manukau (1) and Manawatu (1).

Named after former New Zealand premier Richard Seddon, it featured representative teams from Buller, Nelson Bays, Marlborough, and the West Coast.

It included an overview of the scheme, addressing finance, travel, sponsorship opportunities, implications for club and sub-union competitions, traditional representative matches, international laws and Sunday play.

The remaining provinces, Buller, East Coast, Horowhenua, King Country, Mid Canterbury, Nelson Bays, North Otago, Poverty Bay, South Canterbury, Taranaki, Thames Valley, Waikato, Wairarapa Bush, Wanganui and the West Coast were split into North Island and South Island sub-divisions, with the potential for promotion to the top division.

This remarkable run included a record sixty-one Ranfurly Shield defenses, five South Pacific Championship titles, and recognition as the Halberg Awards Team of the Year in 1992.

In front of a record crowd of 52,000 at Lancaster Park, Canterbury nearly staged a stunning comeback from a 24–0 half-time deficit, but Auckland held on to win 28–23, setting a new benchmark with sixty-one consecutive defences over eight years.

Notable stars like Sean Fitzpatrick, who captained the All Blacks and played 154 games for Auckland, and Grant Fox, who set a record for the most shield points (932), were pivotal during this era, along with John Kirwan, who scored forty-four tries.

The National Provincial Championship would now feature both professional and semi-professional players, comprising the top fourteen financially viable and high-performing regional teams.

For sponsorship purposes, it was rebranded as the Air New Zealand Cup, while the remaining teams formed an amateur competition called the Heartland Championship.

By December 2005, the final pools and draws for the inaugural Air New Zealand Cup were established, with the season commencing in late July.

Centurions such as Owen Franks and Sam Whitelock, along with other notable talents like Wyatt Crockett, Sonny Bill Williams, Codie Taylor and Richie Mo'unga, all began their careers with Canterbury.

Ireland international James Lowe and former All Black Jimmy Cowan both scored tries, converted by Marty Banks, securing a memorable 26–6 victory.

In April 2021, Bunnings, a hardware and retail store, became the new sponsor of the competition, leading to the name's return to the National Provincial Championship for the first time since the 2005 season.

Following a further review by New Zealand Rugby, the competition format was also restructured, allowing fourteen teams to compete for a single title, eliminating the divisions that had been in place since the 2010 season.

[12] Beyond the traditional Super Rugby bases of Auckland, Canterbury, Otago, Waikato and Wellington, only two other provinces have achieved notable success during the professional era, Taranaki and Tasman.

[28] New Zealand owned home improvement and garden retailer, Mitre 10 took over sponsorship in 2016 after they were announced the new title sponsor for the national domestic rugby union competition.

With the inclusion of the Farah Palmer Cup, and support of the Jock Hobbs Memorial National Under-19 tournament, Mitre 10 became the first sponsor of all major fifteens domestic rugby competitions in New Zealand.

[29] Bunnings assumed sponsorship of the tournament on a three-year arrangement prior to the 2021 season, changing the competition's name back to the National Provincial Championship.

[30] In March 2024, the NPC signed a 4-year sponsorship deal with insurance firm Gallagher as an "official national partner" which sees their logo displayed on team jerseys, in stadiums and during televised matches.

[31] The preliminary determination on a proposed salary cap from the Commerce Commission was made public in March 2006, according to the New Zealand Rugby Union.

[32] The hiring of Craig Neil and Cameron Good to the positions of manager and advisor for the salary cap was later confirmed by Steve Tew.

[33] The Commerce Commission was considering overturning its ruling that allowed the New Zealand Rugby Union to impose player movement restrictions and a salary cap.

It was revealed that no matter if a player participates in a single game or not, the minimum worth of any contract is NZD 18,000 and that sum counts towards the salary cap.

For the 2011 season, three midweek games were agreed upon by all provincial teams in a one-off arrangement to accommodate an expanded Super 15 and the Rugby World Cup.

This was necessary because, according to IRB regulations, the World Cup host was required to cease all domestic rugby action a fortnight or more before the beginning of the competition in order to give all venues enough time to display their sponsors' logos.

Andrew Thompson, the chairman of the Taranaki Rugby Football Union board, collaborated with the other provinces to provide a new format to the NZR.

[71] It was also stated that it would be on display for the general public to witness during the competition's opening game, which was played in Napier between Hawke's Bay and Canterbury.

For example, since North Harbour, an Air New Zealand Cup team, held the Shield at the end of the 2006 season despite losing their home quarter-final to Otago, they were forced to defend the Shield against two Heartland Championship teams during the 2007 pre-season, since they had only five home games scheduled in the 2007 Air New Zealand Cup regular season, which they did against Thames Valley and Horowhenua Kapiti.

[82] The Duane Monkley medal, named in honour of the legendary Waikato player who played 135 games for the province between 1987 and 1996, was unveiled by New Zealand Rugby in 2017.