NZRU's manager of the Lions series, Nigel Cass, said most British visitors would spend several weeks in the country.
"The economic benefit will not just be felt in one part of the country. It'll be felt from Invercargill in the south to Auckland because the team is going everywhere," he told the New Zealand Herald.
The tourism industry could also benefit in the long-term as around 200 foreign journalists will accompany the touring side and many will write travel articles alongside their rugby commentary.
Tourism Auckland chief executive Graeme Osborne believes the economic impact of the tour will be huge for his city.
"We know that many visitors will be using Auckland as a base during their stay in New Zealand," he added.
Fifteen thousand overseas visitors are expected during the tour, which runs from June 4 to July 9.