The groundwork for Tahi began more than a decade ago, when Hayes joined EY from a stint at the IRD and then Arthur Andersen, before that firm was merged into Ernst & Young.
He began slowly building up a portfolio and client base around his passion for Maori economic development, creating a team within EY with a focus on helping Maori organisations.
At the time, he says, competing firms were "mildly interested but didn't really pursue the Maori sector.
"I dragged the profession into it because that's what I really wanted to do. Through EY we had some early success and then the competitors started to jump in, which is all good for the sector." Hayes began talking to EY leadership last year about moving beyond a team working on Maori business, to a dedicated firm for Maori clients.
It's a new concept for a major accounting firm in New Zealand but EY had done something similar in the United States, with a firm focused on the African American market, says Hayes.
"It's an independent firm but it's linked into the EY global structure.
"Once I heard that I thought 'okay, this is doable, it's not so crazy'." Hayes surveyed Maori organisations to see where the unmet demand was and whether there was a place for Tahi in the market.
The Maori sector is diverse, he says, but several themes came back.
There were the big players, with a different risk profile, who liked to have the support of a large corporate advisory firm but wanted the clear focus that Tahi's Maori practitioners could provide, says Hayes.
On the other side were Maori organisations who wanted to deal with a Maori firm, preferring not to be writing cheques to big Pakeha corporates, he says.
Hayes saw a place for a hybrid model that could accommodate both ends of the market, and a recent global refresh at EY gave local practices the licence to try something different.
"[EY leadership] took little convincing. In fact they've been pushing it harder than us at times because they're just excited by it."
At this stage Tahi is wholly owned by EY New Zealand, but the goal is to move it into independent ownership. The business is operated by senior Maori accountants from EY bolstered by five external hires, says Hayes.
"We needed to do something different otherwise people would accuse us of just relabelling something." Expanding beyond EY's traditional big city strongholds has seen Hayes, an "eastern Bay of Plenty boy", move from Wellington to Rotorua with his young family to establish a new office, and there is another in Hamilton.
The focus for Tahi over the next three to five years is what Hayes calls the "big bets", which offer a mix of challenge and opportunity for the sector. Tahi is targeting three specific areas: well-designed tribal structures for wealth distribution; a Maori-led defence against "zombie towns"; and decluttering the sector.
Hayes says as tribal organisations become significant business entities, it means more scrutiny from members interested in how that economic success benefits the whole iwi.
Tahi's role will be to help Maori organisations bring more science to their structures, develop strategic plans and long-term financial models.
"Ngai Tahu and Tainui are the first of many that are going to break the billion-dollar mark and we can help accelerate that success, not just commercially but how they distribute the wealth." He says financial success is just a means to further the aims of Maori organisations, which are largely about developing their people and culture.
Zombie towns have received a lot of media coverage but Hayes says that is just the latest label for a long-standing problem in the regions.
He says tribes need to be at the forefront of regional growth plans, pointing to the role Ngai Tahu is playing in the Christchurch rebuild.
"We're very keen to accelerate the successful models that are in New Zealand already and bring more global models to that conversation." The final goal for Tahi is to share its expertise in delivering shared services to iwi organisations in order to cut down overheads and boost efficiencies.
Hayes says a busy practice helping a range of Maori organisations with their big challenges will be a signal that Tahi's offering is what the market wants.
On a personal level he quotes a Maori saying: "My prowess is not the strength of one but the strength of many.
"If our team is successful then I'll be happy."
