People who take a six-month mortgage holiday will see the principal payments temporarily stopped and have the interest added to their mortgage, which could significantly jump up their loan.
Finance Minister Grant Robertson told Newstalk ZB's Mike Hosking this morning that at this stage the Government did not know how many people would take up the offer, which is open to people whose incomes have been affected by the COVID-19 coronavirus.
"The criteria we have put in place, or the banks have put in place is around being affected by Covid-19, and clearly many mortgage holders will have been and will be."
Robertson said the option gave people time and the security of knowing they would not lose their home.
"It just defers the payments but they will end up being added on to the mortgage at the end.
"It is principal and interest so that also will mean a significant bill, but I'm very pleased the banks have stepped up for this and taken that pressure off home owners who are worried about losing their homes for the next few months."
The offer means people's principal payments will be stopped while the interest will be added to the loan.
Claire Matthews, a banking expert at Massey University, told Newstalk ZB people should only take loan holidays if they really needed to.
"If you expect to be paid as normal, then you should continue to pay your loan as normal, because nothing has really changed for you."
Most bank branches to close
Meanwhile most bank branches will shut as the country moves to alert level four.
New Zealand Bankers Association chief executive Roger Beaumont said during the lockdown banks would keep some branches open for limited hours one day a week to meet the needs of customers who cannot use ATMs, phone or online banking.
"This is necessary in the circumstances and subject to review.
"We ask that customers do not visit a bank branch unless absolutely necessary."
Those who come into a branch will only be able to do basic banking. They won't be able to talk about getting a mortgage or have lengthy conversations with staff.
Beaumont said all key banking services would remain available to customers.
"Cash will be available at ATMs, payments systems will function as usual, and financial advice and credit applications will be available.
"You will still be able to conduct banking online or on the phone."
Anyone who was unable to use an ATM or internet banking was urged to call their bank to talk through their needs - but to be patient.
"There will be limited operations at contact centres, so please be patient when phoning your bank's 0800 number if you cannot bank any other way."
A spokesman for Westpac New Zealand said it planned to open 32 branches around New Zealand from 10am to 1pm on Wednesdays during the Level 4 lockdown to provide essential transactional banking services to customers unable to use alternative options.
Its branches will be open as normal today.
Gina Dellabarca, Westpac New Zealand general manager of consumer banking and wealth, said customers should avoid coming into branches unless really necessary.
"We have a range of ways people can bank seven days a week, including ATMs, online banking and through our customer service team in our contact centre.
"A limited number of branches will be open to assist with essential transactional services for customers who are unable to use banking services through another channel."
She said for the health and safety of those customers and its teams, it asked people to consider alternative ways to do their banking, or to postpone non-urgent requests.
"We will continue to help our customers through this difficult time, but we ask them to help us and health authorities by banking remotely where possible."
A spokeswoman for Kiwibank said all of its branches would close from 1pm today, including all of its franchises and agency partners as well.
"For most customers who already use online banking this will mean no change to how they regularly access banking products and services.
But she said the bank knew some customers would be affected and it was "working through what support we can provide".
She said over the next two months the bank would waive fees when customers use its automated phone banking or phone the contact centre.
"We are still working through logistics but during the lockdown some branches may be opened one day a week, for limited hours, to meet the needs of customers who cannot use ATMs, phone or online banking. For updated information customers are best to visit our website for the most up-to-date information."
She said customers who needed to call the bank should use self-service options as much as possible and only contact it if essential.
"For customers needing support there is a call back form on our website, for those ringing our 0800 number there maybe longer than usual wait times. Like many businesses we're operating under the unique constraints of the situation and the availability of our people is limited."
A spokesman for the BNZ said the majority of its branches were open today but all branches would shut temporarily from tomorrow.
From April 2 a select number of branches would open between 10am and 2pm on Thursdays for the period of the lockdown.
"BNZ will advise customers via its online channels and contact centres as to what branches will be open as soon as possible."
Paul Carter, BNZ chief customer officer, said the bank remained open for business.
"Our online banking and digital tools can handle the increase in traffic, our smart ATMs are operating, the majority of our branches are open today and our contact centre is taking calls.
"We've got a dedicated team of people who have put their hands up to staff our branches during the lockdown. Once we've finalised arrangements to protect the health and wellbeing of our staff and ensure the safety of customers, we'll notify our customers as soon as possible as to which branches will be open."
Carter said all key banking services would remain available to its customers during alert level 4.
"Cash will be available at ATMs, payments systems will function as normal, and credit applications will be available."
"We appreciate this is an uncertain time for our customers. We're encouraging them to contact us via our online and digital services and our contact centres and not to come to a branch unless they really need to," he said.
A spokeswoman for the ANZ said 61 of its branches would open 9am to 12noon on Wednesdays starting from April 1 until further notice.
She said services available in the branches would be limited and only available to those who can't do banking through other channels.
"NZ customers can still use internet banking and ANZ's mobile banking app ANZ goMoney to do the majority of their banking, and the contact centre is available seven days a week. Cash will be available at ATMs and customers can use any non-ANZ ATM fee free."
Those who have to go into a branch will be asked to stand on markings on floor to ensure there is physical distancing while waiting in line.
"To protect our customers and employees we ask customers do not visit a branch if they're feeling unwell, have travelled overseas in the last few weeks or if they've been in contact with someone who has – or might have – Covid-19."
The Herald has also contacted other banks to find out when their branches will be open and will update the story as responses come in.