White Island Tours has admitted two charges laid against them over the deadly Whakaari eruption.
The charges, laid by WorkSafe, found the company's risk assessment processes didn't adequately identify the risk of a significant eruption - something White Island Tours has said it "deeply" regrets.
White Island Tours won't be sentenced until the charges against other defendants are resolved.
Twenty-two people died and dozens were injured when the Whakaari/White Island volcano off the coast of Whakatāne erupted in December 2019.
Forty-seven people, mostly tourists, were on the island at the time of the eruption.
WorkSafe, which had charged White Island Tours under the Health and Safety at Work Act 2015, said the guilty pleas' significance "can't be understated".
"The survivors and the families of those tourists and workers who died or were seriously harmed will carry this impact for the rest of their lives. They are always at the front of our minds," WorkSafe chief executive Phil Parkes said.
White Island Tours said the guilty pleas acknowledged "the company's risk assessment processes did not adequately identify the risk of a significant eruption taking place without warning on Whakaari, therefore creating a risk to visitors and employees".
"We were all devastated by the eruption in 2019 and the victims and their whānau remain in our thoughts," director Paul Quinn said.
"In light of this tragedy, we decided that no further guided tours would be taken to Whakaari and all visits ceased from the time of the eruption."
Other parties that had already entered guilty pleas included GNS Science and Inflite Charters.
Another nine parties are set to face trial next month.
