Whangarei SeniorNet spokesman Joe Cross said he had around half a dozen complaints in the last day. He said a lot of them had called the number on the census letter, then been placed on hold before becoming frustrated and hanging up.
"They are getting confused about everything. Elderly do that.
"The letter is clear if they are computer literate, but a lot of them sadly aren't. They are becoming offended that they have to wait for a phone call to get the papers sent out."
SeniorNet national spokesman Grant Sidaway said they were running over 200 workshops nationally to help seniors complete the census.
"We're getting a steady flow of people coming to us asking for help."
2018 Census general manager Denise McGregor said half a million people had completed the online census forms already and elderly Kiwis were well represented in the early submissions.
Around 80 per cent of the country was getting their letters mailed out. While the remaining 20 per cent would have their letters hand delivered like in previous years. McGregor said Cyclone Gita had delayed delivery in some areas and if you haven't got your letter, don't worry, it would be on its way.
The online option was available in both the 2006 and 2013 census'. Last census one third of the country completed it online. This census they were hoping for 70 per cent of people to do it online, McGregor said.
"We think New Zealand is ready for this."
McGregor expected about 94 per cent households to complete the census.
Information from the census helps determine how billions of dollars of Government funding is spent across New Zealand.
The information collected is about everyone in New Zealand, it can be used to inform decisions and make plans about services and where they should be.
Councils, iwi, and businesses also use census information to help work out the core needs of their area or services.
How to participate in the 2018 census
• From today every household will receive an access code letter.
• It contains all the information a household needs to take part in the census online.
• Paper forms will still be available for those who prefer them.
• Once a household receives their letter, they can contact 0800 CENSUS (0800 236 787) to request paper forms, which will be posted to them.
• Stats NZ will include a freepost envelope for them to be returned.
Source: Stats NZ
More information on the census
• The census is an official count of how many people are in New Zealand. It's a snapshot of the people who live here and the places they call home.
• The data collected is used to inform important decisions, including where to spend taxpayers' money on services like schools and hospitals.
• The next census is on Tuesday, March 6, 2018.
• The funding for the 2018 census is spread over five years, totalling $119 million.
Source: Stats NZ