Immigration New Zealand experienced one of its busiest days on Monday as people tried to apply for their visas online before the increase in fees and levies on 1 October 1.
RNZ received reports of the Immigration Online system being down for significant periods of time on Sunday and Monday.
Katy Macleod, Immigration New Zealand (INZ) director online services, said the platform - which mainly handled student, group, partnership and resident visas, exceeded three times the regular traffic that would normally come through the site.
"This meant that some customers experienced intermittent issues when applying for visas through this platform," Macleod said.
"There were no issues reported for customers submitting through our other systems."
She said once INZ was alerted to the problem, it placed a banner on the website advising customers of the issues with the Immigration Online system, and directed customers to the Enhanced Immigration Online system if they were applying for visitor visas.
Macleod said INZ acknowledged that some customers may not have been able to submit their applications before the 1 October cut-off, and apologised for the disruption.
She said the increases to visa fees and levies were well-signalled.
"We communicated with stakeholders and customers well in advance that the government would be increasing visa fees and levies on 1 October 2024, and customers would need to submit complete applications before this date, otherwise they would need to pay the new fee."
In August, the government announced visa fees and levies would be going up to ensure the system was self-funding and more efficient.
Most international visitors applying for a visa or NZETA (New Zealand Electronic Travel Authority) need to pay a non-refundable International Visitor Conservation and Tourism Levy (IVL) to enter New Zealand. That charge increased by $65 to $100 on Tuesday.
Other visas also increased markedly, with skilled residence visas and partnership visas each climbing by more than $2000, while student visas doubled to $750.