Education providers are questioning why Education New Zealand is not calculating the cost of visa delays to the sector.
A proposed new dairy farming school in Ōamaru has been put on hold because of visa processing problems.
The National Trade Academy (NTA), which trains and places 80 to 120 immigrants in farms every year, also had to cancel a course intake in Christchurch.
The Institutes of technology and polytechnics (ITPs) sector estimated in March it had lost an estimated $33 million in fees in only four months.
One education provider, Aspire2 International, said those losses were continuing.
It had lost more than $3 million because of the visa processing delays, which began last summer.
The delays and visa rejections had risen since then, and agents were turning to markets with better visa timelines and consistency, said its chief executive, Clare Bradley.
She was mystified by Education New Zealand not collecting information on the costs to international education, she said.
"It's probably something we should all be asking, that they should have updated that analysis," she added.
"We are nearly 300 students off the pace when I compare to the same time last year. It isn't getting better.
"In fact, what we're seeing is a real deepening of the wound. Two things are creating greater damage or continuing damage - one is the ongoing delays with visas, because it's still taking longer than it used to, to process visas.
"And the other is the increased decline rates across markets, which means that students who are considering coming to New Zealand are looking for places that are more consistent in their decision making and easier to do business with."
The Indian market was particularly affected, she said, and education providers were suffering.
"I can see that request for offers of place are considerably down. The feedback from our agent network is that they're waiting for things to improve that they not prepared to put students through a process where they don't feel confident in the way in which it is being managed."
Frustration was felt not just in education, but also in the tourism sector because of delayed visitor visas and from businesses needing work visas, she added.
Hold-ups at Immigration New Zealand, caused by an increase in visa applications last year at the same time it was streamlining its worldwide offices, have led to axed courses and holiday bookings.
The NTA's managing director, Craig Musson, who is also chair of the sector group Independent Tertiary Education, said it was waiting for 50 visas to be processed at Palmerston North so could not open its new site in Ōamaru.
After their courses, they place all of their students on farms, he said, so there would be fewer agricultural workers as a result.
He estimated the visa issues have cost the academy $60,000 and the new dairy farming school would have added an estimated $400,000 to the Ōamaru economy.
"Certainly, it's hurt us as we lost $60,000 because we had to postpone one course. And that hurts. That also means that there's 11 students that weren't able to have the opportunity to come and train and go through.
"I've told the council that I won't be going ahead with that farming school, unless I get more security of knowledge that my students are going to get visas.
"So these employers are going to miss out on opportunities, and also the amount of money that brings into the Ōamaru and Waitake district with us running three or four agriculture courses per year."
Education New Zealand said in a statement it has not done any modelling of the cost of visa processing to tertiary institutions.
"Our role is to monitor and surface any issues with providers and agencies," said its general manager of stakeholders and communications, John Goulter.
"We do have a joint work programme in place with Immigration New Zealand to coordinate market strategies, provide market guidance for education providers and improve student visa outcomes."
Immigration New Zealand (INZ) said in a statement the approval rate for institutes of technology and polytechnics dropped from 79 percent last year to 56 percent this year.
Its national manager for education and tourism, Jeannie Melville, said there had been an increase in applications and more were being rejected.
"The drop in approval rates reflects the increased number of applications received that did not contain the information INZ needed to make a decision, and/or those that were complex and presented risks.
"INZ is continuing to see applications where it would appear that little due diligence is being done by providers before offering a place and/or students do not have the financial means to maintain themselves while they are in New Zealand.
"The queue of student visa applications from earlier in 2019 has been cleared in Mumbai and applications are being allocated to an immigration officer for assessment within 10 working days."
It was confident it had the staffing needed to address the predicted volume of visas before the next peak in student applications, she said.
It had also collaborated with Education New Zealand on a student visa checklist to provide guidance about the type of evidence and supporting information it needed.