New Zealand has got its first fully digital bank, with global financial services firm Revolut gaining banking registration from the Reserve Bank on Tuesday.

Revolut, which has 80 million customers worldwide, has committed to investing $120 million in its local operations.

The digital-only service will offer New Zealanders instant-access savings accounts for personal and business customers, which are protected by New Zealand's Depositor Compensation Scheme.

In its latest funding round, the London-based company was valued at $US115 billion ($NZ204b), making it the United Kingdom's most valuable fintech.

The bank is hoping to challenge the dominance of the big four Australian-owned high street banks, which hold over 80% of market share.

It has been operating in New Zealand as a financial services firm since 2023 and will now become the 27th bank in New Zealand.

"The Reserve Bank recognises the value that credible new entrants can bring to a competitive, resilient, inclusive and efficient financial system, and we are pleased Revolut NZ has met the required standard for bank registration in New Zealand," Reserve Bank director of specialist supervision Scott McKinnon said.

Nik Storonsky, founder and chief executive of Revolut, said launching a New Zealand bank was a significant step in its goal to be the world's largest digital bank.

"Securing our seventh bank licence, and our fifth this year alone, is a testament to our business model and our team. We are confident our offering will bring true competition to the New Zealand banking sector."

Storonsky called it a defining moment.

"Since launching here in 2023, we have experienced massive growth. It's clear the market is primed for disruption, and this licence is the launchpad for our next chapter as we continue to build a seamless, secure and customer-first banking experience in Aotearoa."

Credit ratings agency S&P Global has assigned Revolut an investment-grade BBB+ long-term credit rating, with a positive outlook.