There are three confirmed challengers looking to wrest the coveted trophy from the Kiwis, who won it from Larry Ellison's Oracle Team USA in Bermuda in 2017.
Only one crew will ultimately go forward to race New Zealand in a best-of-13 head-to-head series which will be fought out between the winner of the newly launched Prada Cup and the defender.
The Royal New Zealand Yacht Squadron and Emirates Team New Zealand said in a statement on Friday that an additional eight "Notices of Challenge" had been received by the deadline at 5:00 pm New Zealand local time (0400 GMT).
There has been speculation among other America's Cup entrants that further challenges would emerge by the deadline, with rumours of a second U.S. entry, a Chinese team, a French crew and a Dutch challenge.
Team New Zealand did not name or identify any of the new entries but said only one of them is immediately eligible to be accepted, while others are likely to be invalid and not all are expected to make it through a vetting process, which will begin immediately.
"We must not jump to conclusions on the final number of teams. It is only when the acceptance process has been completed that we will know how many will compete in the Prada Cup alongside Luna Rossa, American Magic & INEOS Team UK," said Emirates Team New Zealand CEO Grant Dalton.
Conditions included by some of the challenges will require changes to the America's Cup Protocol and this will depend on it being agreed with Luna Rossa, which is the so-called Challenger of Record under the complex rules of the Cup, which began in 1851.
Such conditions could, for instance, include holding an America's Cup World Series event in a challenger's own country, Dalton added.
Deciding how many entries are valid will have a knock-on effect for preparations in Auckland, where the cost and development of the facilities for the event is politically sensitive.
"We want to act quickly with the Challenger of Record so we can definitively inform Council and Government on the total number of teams we need to accommodate or whether it is sensible not to extend Hobson Wharf in this current edition of the America's Cup, which could save a significant amount of infrastructure expense,' Dalton said.
(Reporting by Alexander Smith, editing by Louise Heavens)
